LT1-LT4 Modifications 1993-97 Gen II Small Block V8

misfire because of a p0100 code?

Thread Tools
 
Search this Thread
 
Old 03-29-2008, 07:16 PM
  #1  
Staging Lane
Thread Starter
 
simster571's Avatar
 
Join Date: Feb 2008
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
Default misfire because of a p0100 code?

ok so I just installed my headers last week..got the rest of the exhaust componets on, everything back together (except I left my rear 02 sensors off...im going to get simulators) and now it really feels like my car is misfiring..especially at low rpm with high throttle. The car never did this before and ran great before I did this header swap. So once I had the headers on and drove it around and found out it felt like it was misfiring, I just assumed that either one of the spark plug wires got burnt through or I has accedently switched 2 of them up. So i went and bought boot protectors and new spark plug wires and installed them. All new wires with heat boots on the end of them. I am pretty sure that I have them all in the right spot because I did it one at a time and its kinda hard not to being as they are all diffrent lenths. So im about 90% sure its not the wires or the wiring order. I took my car to autozone to have them run the code check, and i assumed it was going to bring up a misfire on whatever cylinder was having the problem and of course my rear O2's. Well turns out, neither of those that I expected came up, and instead I was getting a P0100 - Mass Air Flow (MAF) Circuit Malfunction code. WTF? Would fixing this likely solve my misfiring problem? and maybe it isnt even misfiring being as it didnt throw a code for it...but it also didnt throw the O2 codes which kinda makes me think i just havent driven it around enough for it to code. What do you guys think?
Old 03-29-2008, 07:44 PM
  #2  
On The Tree
 
ryanisfast's Avatar
 
Join Date: Mar 2007
Location: Tacoma, WA
Posts: 198
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by simster571
ok so I just installed my headers last week..got the rest of the exhaust componets on, everything back together (except I left my rear 02 sensors off...im going to get simulators) and now it really feels like my car is misfiring..especially at low rpm with high throttle. The car never did this before and ran great before I did this header swap. So once I had the headers on and drove it around and found out it felt like it was misfiring, I just assumed that either one of the spark plug wires got burnt through or I has accedently switched 2 of them up. So i went and bought boot protectors and new spark plug wires and installed them. All new wires with heat boots on the end of them. I am pretty sure that I have them all in the right spot because I did it one at a time and its kinda hard not to being as they are all diffrent lenths. So im about 90% sure its not the wires or the wiring order. I took my car to autozone to have them run the code check, and i assumed it was going to bring up a misfire on whatever cylinder was having the problem and of course my rear O2's. Well turns out, neither of those that I expected came up, and instead I was getting a P0100 - Mass Air Flow (MAF) Circuit Malfunction code. WTF? Would fixing this likely solve my misfiring problem? and maybe it isnt even misfiring being as it didnt throw a code for it...but it also didnt throw the O2 codes which kinda makes me think i just havent driven it around enough for it to code. What do you guys think?

I also have this code in my car ever since I installed the headers. At first my car ran fine, then it started missing like what you're saying. Although, since I awas already throwing the code and it ran fine I'm beginning to think that it's really just my opti or the coil. I tried a another maf sensor to and I still threw the 0100 code. Maybe we were idiots and burnt the wire. Maybe it's routed near the headers. I don't know. Can someone with knowledge shed some light in this direction??
Old 03-29-2008, 07:46 PM
  #3  
On The Tree
 
ryanisfast's Avatar
 
Join Date: Mar 2007
Location: Tacoma, WA
Posts: 198
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by simster571
ok so I just installed my headers last week..got the rest of the exhaust componets on, everything back together (except I left my rear 02 sensors off...im going to get simulators) and now it really feels like my car is misfiring..especially at low rpm with high throttle. The car never did this before and ran great before I did this header swap. So once I had the headers on and drove it around and found out it felt like it was misfiring, I just assumed that either one of the spark plug wires got burnt through or I has accedently switched 2 of them up. So i went and bought boot protectors and new spark plug wires and installed them. All new wires with heat boots on the end of them. I am pretty sure that I have them all in the right spot because I did it one at a time and its kinda hard not to being as they are all diffrent lenths. So im about 90% sure its not the wires or the wiring order. I took my car to autozone to have them run the code check, and i assumed it was going to bring up a misfire on whatever cylinder was having the problem and of course my rear O2's. Well turns out, neither of those that I expected came up, and instead I was getting a P0100 - Mass Air Flow (MAF) Circuit Malfunction code. WTF? Would fixing this likely solve my misfiring problem? and maybe it isnt even misfiring being as it didnt throw a code for it...but it also didnt throw the O2 codes which kinda makes me think i just havent driven it around enough for it to code. What do you guys think?

I also have this code in my car ever since I installed the headers. At first my car ran fine, then it started missing like what you're saying. Although, since I awas already throwing the code and it ran fine I'm beginning to think that it's really just my opti or the coil. I tried a another maf sensor to and I still threw the 0100 code. Maybe we were idiots and burnt the wire. Maybe it's routed near the headers. I don't know. Can someone with knowledge shed some light in this direction??

Also the pcm resets itself every now and then. So, sometimes the code for rear 02's will show up and sometimes it won't. Just depends.
Old 03-29-2008, 09:21 PM
  #4  
Staging Lane
Thread Starter
 
simster571's Avatar
 
Join Date: Feb 2008
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
Default

When I was out working on it I noticed my EGR gasket....the one that goes inbetween
the headers and the egr part that connects to the headers...could this be causing misfire?
Old 03-30-2008, 11:32 AM
  #5  
Staging Lane
 
stfuad's Avatar
 
Join Date: Jun 2007
Location: Syracuse, NY
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default

Take care of any vacuum/exhaust leaks clear the code and go through a drive cycle before you spend anymore money on stuff you don't need.

If the code comes back backprobe the maf connection and check to see your getting the right voltage etc...

If you tried using another MAF and it still didn't work check the wires for continuity.

I doubt a bad egr gasket would cause an unrelated code.

If you don't already have a nice multimeter go buy one.

Honestly if your throwing codes you should take care of them asap and not assume that because nothing seems to be going wrong it isn't. Using a tree method to deduce problem is the best way to go.



Quick Reply: misfire because of a p0100 code?



All times are GMT -5. The time now is 03:06 PM.