Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

help random misfire

Thread Tools
 
Search this Thread
 
Old Jan 25, 2009 | 01:34 PM
  #1  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Exclamation help random misfire

Ok heres the story, i took my car to the wash to get all the road salt off the car,(drive thru undercarriage wash) so im in there getting washed and the idle starts getting rough (no problem it always did in the drive thru) so i drive off and it goes away like every other time BUT....now any hill under light throttle bucks a little so i press a little more on the pedle and it drops in passing gear i hold steady for like 2 seconds and it clears up and takes off. so its friday 01/23/09 lunch time at work and i start the car ses light is flashing random misfire is on the code reader so i take it home to try to fix it, no luck. heres what ive do thus far.....checked all connections to all sensors, removed icm and coils. coils are .7 or better checked all plug wires no burns. so what i want to know is or what im thinking is some how water got some where and is goofing things up like crank sensor or cam sensor any help to keep this poor boy out of the dealer would be great thanks.
Reply
Old Jan 25, 2009 | 01:46 PM
  #2  
7camaro7's Avatar
TECH Resident
iTrader: (15)
 
Joined: Oct 2006
Posts: 910
Likes: 0
From: Tennessee
Default

unplug all plug wires make sure they're dry. Get some di-electric gel and put some in each end of each wire. Plug them back up. If you have long tubes make sure your o2 sensors are tight. Check the o2 connections for water too. I had a problem like this before after cleaning under the car and it fixed my problems. Never has come back.
Reply
Old Jan 25, 2009 | 02:00 PM
  #3  
W es 6's Avatar
On The Tree
iTrader: (1)
 
Joined: Feb 2008
Posts: 196
Likes: 0
Default

+1 on the o2 sensors... when my car threw that code, it was my o2's.
Reply
Old Jan 25, 2009 | 03:26 PM
  #4  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by W es 6
+1 on the o2 sensors... when my car threw that code, it was my o2's.
what code did your car throw?
Reply
Old Jan 25, 2009 | 03:31 PM
  #5  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Talking

Originally Posted by hevymetalg
what code did your car throw?
btw my car is a 98 v6 camaro, im in the middle of changing all plugs and of course they smell of gas and look a little black but good so prob wasting my time and money.
Reply
Old Jan 25, 2009 | 03:52 PM
  #6  
7camaro7's Avatar
TECH Resident
iTrader: (15)
 
Joined: Oct 2006
Posts: 910
Likes: 0
From: Tennessee
Default

exhaust leak at the manifolds or o2s
Reply
Old Jan 25, 2009 | 04:44 PM
  #7  
Bill Bowling's Avatar
TECH Addict
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (6)
 
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Default

I had the same problem after going thru some water. It was a O2 bad.

Bill
Reply
Old Jan 25, 2009 | 05:16 PM
  #8  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by Bill Bowling
I had the same problem after going thru some water. It was a O2 bad.

Bill
thats what im thinking. heres what i did:

I did change all the plugs and it fired right and idles perfect now but under load it still throws the random misfire code. the passenger side plugs were all gas and wet looking the driver side was dry if that sparks someones mind let me know?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Jan 25, 2009 | 05:41 PM
  #9  
W es 6's Avatar
On The Tree
iTrader: (1)
 
Joined: Feb 2008
Posts: 196
Likes: 0
Default

what code did your car throw?
It was P0300 Random Multiple Misfire. For me it was caused after my header install.

Your front o2's essentially tell the engine how to run based on analyzing the exhaust gases. If your o2's are messed up, they will more than likely be sending the wrong signals back to your PCM, which in turn will cause it to run horribly wrong on one or both banks. This could explain why one bank of spark plugs had a shitload of gas on them. I think there's a good chance that if you replace your o2's you'll fix the problem. Just my .02
Reply
Old Jan 25, 2009 | 06:27 PM
  #10  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by W es 6
It was P0300 Random Multiple Misfire. For me it was caused after my header install.

Your front o2's essentially tell the engine how to run based on analyzing the exhaust gases. If your o2's are messed up, they will more than likely be sending the wrong signals back to your PCM, which in turn will cause it to run horribly wrong on one or both banks. This could explain why one bank of spark plugs had a shitload of gas on them. I think there's a good chance that if you replace your o2's you'll fix the problem. Just my .02
thanks thats next after new wires and coils.
Reply
Old Jan 25, 2009 | 09:03 PM
  #11  
W es 6's Avatar
On The Tree
iTrader: (1)
 
Joined: Feb 2008
Posts: 196
Likes: 0
Default

no problem good luck with the fix!
Reply
Old Jan 26, 2009 | 06:54 PM
  #12  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by W es 6
no problem good luck with the fix!
thanks everybody im taking a break and regrouping this weekend. GETTING GOOD NEW WIRES.
Reply
Old Jan 27, 2009 | 04:15 PM
  #13  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

orderd msd wires
Reply
Old Jan 29, 2009 | 08:10 PM
  #14  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by Bill Bowling
I had the same problem after going thru some water. It was a O2 bad.

Bill
did it throw a o2 sensor code?

Originally Posted by hevymetalg
thanks everybody im taking a break and regrouping this weekend. GETTING GOOD NEW WIRES.
have not started the car till today to see if it still would idle and it didnt! wtf!!!! i didnt change the wires yet but thought it should still idle......
Reply
Old Jan 31, 2009 | 09:59 AM
  #15  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

going out to put new wires on to see if its the problem ill keep yas posted.....
Reply
Old Jan 31, 2009 | 01:16 PM
  #16  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

Originally Posted by hevymetalg
going out to put new wires on to see if its the problem ill keep yas posted.....
ok changed all wires and now it idles till it warms up, then it revs up and down (once it warms up) and i got two codes random misfire and o2 senser circuit malfunction. i now have one question what side is bank 1 and what side is bank 2? my car is 98 v6 3800 series 2 thanks (going to get an o2 senser)
Reply
Old Jan 31, 2009 | 08:45 PM
  #17  
00silver6's Avatar
12 Second Club
iTrader: (4)
 
Joined: Nov 2005
Posts: 387
Likes: 0
Default

bank one driver side
Reply
Old Feb 1, 2009 | 08:59 AM
  #18  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

got o2 sensor, going to put it in the guy at the auto store said if its bank 2 sensor 1 its a downstream o2 sensor dont sound right to me what do you all think?
Reply
Old Feb 1, 2009 | 09:12 AM
  #19  
Texas 02 Z28's Avatar
TECH Apprentice
iTrader: (14)
 
Joined: Jun 2007
Posts: 328
Likes: 0
From: Austin, TX
Default

Dude, I was throwing random misfire codes too, it ended up being water in the connection of the driver side 02 sensor. Where the 24" extension plugged into the 02 sensor, there was maybe a few drops of water, lol. Just enough to **** my week up and make me buy new plugs/wires for no reason.

I bought 2 new 02 sensors, unplugged the driver side one, found the water in the connection (it was green, iirc, lol), blew it out, plugged it back in and the car ran perfect, lol.

Good luck dude, hope you find it.
Reply
Old Feb 1, 2009 | 03:58 PM
  #20  
hevymetalg's Avatar
Thread Starter
Launching!
iTrader: (1)
 
Joined: May 2008
Posts: 268
Likes: 0
From: lancaster pa.
Default

ok new plugs,wires, o2 sensor, and now new icm still random misfire. whats next to buy? please help!!!!!!
Reply



All times are GMT -5. The time now is 08:56 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE