Random Misfire P0300 started today in the RAIN - LS1TECH

Go Back   LS1TECH > CHASSIS, SUSPENSION, APPEARANCE > General Maintenance & Repairs
Sign in using an external account
Register Forgot Password?
Search


General Maintenance & Repairs
Leaks | Squeaks | Clunks | Rattles | Grinds
Sponsored by
Gearstar Performance Transmissions

Random Misfire P0300 started today in the RAIN

Reply
 
Thread Tools Search this Thread
Old 11-04-2010, 07:31 PM   #1
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default Random Misfire P0300 started today in the RAIN

Is it the 02 sensors??? I've mostly been getting P0300. I got a Misfire on Cylinder #1 code, and a P0113 IAT sensor code. P0300 keeps coming up and its running like its only working on 3 or 4 cylinders. Its pretty bad. It's been raining constantly today and the misfire randomly started today. What do you guys think?

Car is 02 Z28
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 08:39 PM   #2
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

any 1?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 08:46 PM   #3
10 Second Club
 
tording99Z28's Avatar
 
Trader Rating: 3
Join Date: Nov 2007
Location: Hampton, VA
Posts: 1,033
Send a message via AIM to tording99Z28 Send a message via Yahoo to tording99Z28
Default

If you have a misfire on Cylinder 1 then I am sure its cylinder 1. You probably have a fouled plug or a bad wire on cylinder 1. Check the wire first and make sure its on securely on the plug and on the coil pack.
__________________
Project Rogue - Black on Black 99 A3 Z28-Forged 390 cu in LQ9-TFS 220 Heads-Performabuilt RMVB TH400 w/ transbrake-Circle D
2A 4000 stall converter-3.25 MWC 9" rear-Magnafuel fuel system-Garrett GT91-FMIC
14 psi - 10.26 @ 141.42 w/ 1.70 60' @ FMP : 780 rwhp 20 psi - 1005 rwhp/826 rwtq Tyler Hampton Roads VA Fbody Site
tording99Z28 is offline   Reply With Quote
Old 11-04-2010, 08:50 PM   #4
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

yeah the cylinder 1 code came on only once. Random Misfire comes on now. I'll check it again right now. Thanks for the advice.
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 08:51 PM   #5
10 Second Club
 
tording99Z28's Avatar
 
Trader Rating: 3
Join Date: Nov 2007
Location: Hampton, VA
Posts: 1,033
Send a message via AIM to tording99Z28 Send a message via Yahoo to tording99Z28
Default

I would still check #1 first then if you don't find anything check the others.
__________________
Project Rogue - Black on Black 99 A3 Z28-Forged 390 cu in LQ9-TFS 220 Heads-Performabuilt RMVB TH400 w/ transbrake-Circle D
2A 4000 stall converter-3.25 MWC 9" rear-Magnafuel fuel system-Garrett GT91-FMIC
14 psi - 10.26 @ 141.42 w/ 1.70 60' @ FMP : 780 rwhp 20 psi - 1005 rwhp/826 rwtq Tyler Hampton Roads VA Fbody Site
tording99Z28 is offline   Reply With Quote
Old 11-04-2010, 09:15 PM   #6
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

I just went out to check it/test drive it again. Was running fine for 1 minute then started missing again. I checked the code it random misfire came up again. Just P0300. When I had a 98 Z28 this same problem happened and it turned out to be the 02 sensors. I'll check cylinder 1 tomorrow. Should I try swapping the plug and plug wire to cylinder 2 and see if that code comes up? Fuel injectors are fine.
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 09:17 PM   #7
10 Second Club
 
tording99Z28's Avatar
 
Trader Rating: 3
Join Date: Nov 2007
Location: Hampton, VA
Posts: 1,033
Send a message via AIM to tording99Z28 Send a message via Yahoo to tording99Z28
Default

its possible its an O2 sensor but but I would check the cylinder it called out first then if that doesn't fix it then check them all. Yes you could try swapping the plug wire to a different cylinder and see if it the code changes to a different cylinder. How old are the plugs and wires? If they are original then might be as good time as any to just replace them.
__________________
Project Rogue - Black on Black 99 A3 Z28-Forged 390 cu in LQ9-TFS 220 Heads-Performabuilt RMVB TH400 w/ transbrake-Circle D
2A 4000 stall converter-3.25 MWC 9" rear-Magnafuel fuel system-Garrett GT91-FMIC
14 psi - 10.26 @ 141.42 w/ 1.70 60' @ FMP : 780 rwhp 20 psi - 1005 rwhp/826 rwtq Tyler Hampton Roads VA Fbody Site
tording99Z28 is offline   Reply With Quote
Old 11-04-2010, 09:24 PM   #8
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

I just got the car in May. The wires are gray and I believe they are original. Car has 76000 miles. Also, after driving it smells like burnt toast in the engine bay. It almost smells like a burnt clutch. Any ideas?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 09:55 PM   #9
TECH Regular
 
Kevin01Z28's Avatar
 
Trader Rating: 8
Join Date: Mar 2008
Location: Fort Polk, LA
Posts: 422
Send a message via Yahoo to Kevin01Z28
Default

I agree, check the number 1 cylinder first. How bad is the miss? Does it feel like one cylinder, or is it just running like total **** (like a whole bank is missing)?

If you had a way of logging the car, or even a handheld tuner where you could see the O2's mv readings you could easily rule those out. You could however wait till the car cools completely, crank it up and drive it before it warms up and falls into closed loop and see if it misses. If it doesn't miss at first and immediately does after its warm, then there you go. I just got a P0300 code today, because of a bad o2 senser...
__________________
2008 F150 STX Daily driver.
1996 Z28 LS1, bolt-ons, FLT-L4, Circle-D 2B, UMI suspension, 3.42s, HPT

Last edited by Kevin01Z28; 11-04-2010 at 10:15 PM..
Kevin01Z28 is offline   Reply With Quote
Old 11-04-2010, 10:03 PM   #10
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

yeah it runs fine when its cold then goes into miss mode. Feels like a whole bank! Runs like total ****. 02?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 10:14 PM   #11
TECH Regular
 
Kevin01Z28's Avatar
 
Trader Rating: 8
Join Date: Mar 2008
Location: Fort Polk, LA
Posts: 422
Send a message via Yahoo to Kevin01Z28
Default

Quote:
Originally Posted by AgentLS1Z View Post
yeah it runs fine when its cold then goes into miss mode. Feels like a whole bank! Runs like total ****. 02?
Sounds like it to me.. You know anyone that has something you can check them with?
__________________
2008 F150 STX Daily driver.
1996 Z28 LS1, bolt-ons, FLT-L4, Circle-D 2B, UMI suspension, 3.42s, HPT
Kevin01Z28 is offline   Reply With Quote
Old 11-04-2010, 10:30 PM   #12
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

I could bring it to a mechanic. Is there anyway I can check them? Can I switch the front ones to the back?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-04-2010, 10:41 PM   #13
TECH Regular
 
Kevin01Z28's Avatar
 
Trader Rating: 8
Join Date: Mar 2008
Location: Fort Polk, LA
Posts: 422
Send a message via Yahoo to Kevin01Z28
Default

Quote:
Originally Posted by AgentLS1Z View Post
I could bring it to a mechanic. Is there anyway I can check them? Can I switch the front ones to the back?
Front and rears are not interchangable. For what is costs a mechanic to diagnose it you could buy one. I would rather do that, I don't trust anyone with my car. You already have the misfire code. It may take some time to throw a code for the oxygen sensor, mine hasn't yet
__________________
2008 F150 STX Daily driver.
1996 Z28 LS1, bolt-ons, FLT-L4, Circle-D 2B, UMI suspension, 3.42s, HPT
Kevin01Z28 is offline   Reply With Quote
Old 11-05-2010, 08:53 AM   #14
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

Oh okay...how bad is it to drive the car with misfires?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-05-2010, 10:24 AM   #15
TECH Regular
 
Kevin01Z28's Avatar
 
Trader Rating: 8
Join Date: Mar 2008
Location: Fort Polk, LA
Posts: 422
Send a message via Yahoo to Kevin01Z28
Default

Depends on how bad it is. Lockup with be disabled, and depending on your stall size will depend on how much extra heat is built in your tranny. Could foul plugs if its running rich on that bank...and being pig rich isn't the best thing for cats. You could remove the o2 sensors and see if they have any build up on them and clean them, worth a shot.
__________________
2008 F150 STX Daily driver.
1996 Z28 LS1, bolt-ons, FLT-L4, Circle-D 2B, UMI suspension, 3.42s, HPT
Kevin01Z28 is offline   Reply With Quote
Old 11-05-2010, 11:59 AM   #16
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

Is it possible that the fuel filter is clogged? I ran my car on empty for a while a couple days ago. The fuel needle was way below E. I put a bottle of Techron Fuel System Cleaner in the tank hoping that would be my problem. Just now the car was running fine up and down the highway and all the power came back. When I went to start it again later the misfire came back and is constantly there. I think I may go with new 02s. Should I get 4 new ones?
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-05-2010, 02:21 PM   #17
TECH Regular
 
Kevin01Z28's Avatar
 
Trader Rating: 8
Join Date: Mar 2008
Location: Fort Polk, LA
Posts: 422
Send a message via Yahoo to Kevin01Z28
Default

Quote:
Originally Posted by AgentLS1Z View Post
Is it possible that the fuel filter is clogged? I ran my car on empty for a while a couple days ago. The fuel needle was way below E. I put a bottle of Techron Fuel System Cleaner in the tank hoping that would be my problem. Just now the car was running fine up and down the highway and all the power came back. When I went to start it again later the misfire came back and is constantly there. I think I may go with new 02s. Should I get 4 new ones?
If you cant remember the last time you changed the filter I would change it. I would leave the rears alone until you get a code for them...I assume you have cats. You could buy one sensor and see if you get lucky the first try, then swap sides if the miss doesn't go away. I doubt both of them are bad.
__________________
2008 F150 STX Daily driver.
1996 Z28 LS1, bolt-ons, FLT-L4, Circle-D 2B, UMI suspension, 3.42s, HPT
Kevin01Z28 is offline   Reply With Quote
Old 11-05-2010, 02:42 PM   #18
On The Tree
 
MR_M's Avatar
 
Trader Rating: 5
Join Date: Nov 2010
Location: Tahlequah, OK
Posts: 184
Default

Quote:
Originally Posted by AgentLS1Z View Post
Is it the 02 sensors??? I've mostly been getting P0300. I got a Misfire on Cylinder #1 code, and a P0113 IAT sensor code. P0300 keeps coming up and its running like its only working on 3 or 4 cylinders. Its pretty bad. It's been raining constantly today and the misfire randomly started today. What do you guys think?

Car is 02 Z28
Does the car have headers? Water could be getting on the o2 sensor wires causing the misfire. When it rained, my last car would misfire occasionally. Turns out, my o2 sensor wire extensions connections were getting wet. If you don't have extensions it'd be worth checking the condition of the wires to make sure they're not getting water into the connections/wire itself.
__________________
2000 Formula Hardtop M6 MRM
MR_M is offline   Reply With Quote
Old 11-07-2010, 03:30 PM   #19
On The Tree
 
Trader Rating: 0
Join Date: Jul 2008
Posts: 187
Default

Quote:
Originally Posted by MR_M View Post
Does the car have headers? Water could be getting on the o2 sensor wires causing the misfire. When it rained, my last car would misfire occasionally. Turns out, my o2 sensor wire extensions connections were getting wet. If you don't have extensions it'd be worth checking the condition of the wires to make sure they're not getting water into the connections/wire itself.

No the car doesn't have headers.

I changed the fuel filter and the car was running good. But now the misfire is back. I'm not sure what the problem is but i'm leaning towards it being an 02 Sensor. I'll scan the codes again asap
__________________
1998 Z28 A4 2.73's, Custom CAI, Taylor Wires, Tr55s, Pacesetter LTs, ORY, LM2, !Cats, !EGR, !AIR, !Filter Plate. Mail Order Tune from Frost. (Sold)
1996 SVT Cobra Blk on Blk, 5 speed, SLP catback, high flow cats (Sold)
2002 Z28 A4, Free Mods done
Soon to come: SLP LM1 Catback, Pacesetter Coated Headers, Y pipe with high flow cats, MTI Clear Lid, Smooth Bellows, New Plugs, New Wires, Polyurethene motor mounts, mail order TUNE from Frost
AgentLS1Z is offline   Reply With Quote
Old 11-07-2010, 03:51 PM   #20
TECH Fanatic
 
Trader Rating: 70
Join Date: Oct 2005
Location: Los Angeles, California (818)
Posts: 1,219
Default

Quote:
Originally Posted by AgentLS1Z View Post
No the car doesn't have headers.

I changed the fuel filter and the car was running good. But now the misfire is back. I'm not sure what the problem is but i'm leaning towards it being an 02 Sensor. I'll scan the codes again asap
i have the same issue random missifres.

i changed the front o2s on both sides and still. changed fuel rails and fuel injectors and still also changed spark plugs and wires and still.

im beggining to think it may be ground related?
__________________
[FONT="Arial Black"][FONT="Arial"][SIZE="1"][B]1998 NBM Z28 (ANY CAR CAN BE AN SS, BUT ONLY A CAMARO CAN BE A Z28)
themack56 is offline   Reply With Quote
Old 11-07-2010, 03:51 PM
LS1Tech
Pontiac Firebird




Paid Advertisement
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need some help- P0300, P0301, P0304 ARaver PCM Diagnostics & Tuning 1 11-30-2013 09:56 PM
Misfire help!! barkerpa3466 General Maintenance & Repairs 11 10-21-2012 05:27 PM
P0300 Multiple misfire code - check individual cylinders? Leeet Generation III Internal Engine 5 08-15-2011 09:52 AM
P0301 misfire...this is involved AgentLS1Z General Maintenance & Repairs 24 12-16-2010 06:10 PM
Throwing P0300 and P0171 Codes, Help gunit PCM Diagnostics & Tuning 2 05-30-2009 09:34 AM


Tags
1996, 96, code, coil, driving, egr, misfiers, misfire, misses, pack, rain, random, test, throws, z28


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off



Join Ls1Tech

All times are GMT -5. The time now is 04:07 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Advertising - Terms of Service - Privacy Statement - Terms of Service - JOBS
Emails & Contact Details