Ever since I installed my long tube headers my car has run like ****. I will try and make this short as possible but here goes:
I originally was running mac shorty headers, no cats, and pcmforless OBD2 tuning. I then installed new hooker longtubes with mufflex y-pipe. After this my car seemed to run ok but still didnt seem powerful. I went to the track and found I ran .4 tenths and 3mph slower than my previous best with shorties. Ok something isnt right. On the way home from the track my SES light came on it was code P1133 (H02S Insufficient switching Sensor 1/bank 1 Fuel control shifted lean). After reading this code I immediately thought it was a bad 02 sensor which seemed reasonable as I had some cheap ones in there. I bought 2 new GM 02 sensors and this did nothing. I still received the same code P1133. Now I thought just maybe I happened to get a bad sensor from GM so I swapped sides and then SES came on again. I get the car scanned and now im getting 3 codes: P0133 (Bank 1/ Sensor 1 02 slow response), P1153 (Bank 2 control shifted lean), and then P1133 again which is same code as previously mentioned above. Guy at the shop said its still possible that its a bad 02 and by switching sides it triggered other codes P1153 being the frist one which is bank 2 which was originally the sensor which triggered the original code. I used a pair of my friends old 02 extension wires which could be bad but most likely not. No 02 wires are burnt or touching anything hot. I also replaced the plugs, new wires, tried a different opti and coil, new fuel filter, and just installed a brand new OBD1 conversion PCM thinking that maybe the car was leaned out for my shorties and now with long tubes was running to lean so the computer ran in "safe mode" and richened the mixture a lot. So after installing the OBD1 conversion PCM I was excited thinking everything would be fixed, wrong. The car seems to run pretty smooth and strong at WOT, however during normal acceleration it stutters (you can literally feel the car loose power, then add it again it actually jolts you back and forth during acceleration). Since 02 sensors are not read at WOT this is why im still leaning towards something wrong with one of my new 02's or the old 02 extensions. Well, from hearing my situation, and the codes im getting can anyone give me some more info this car is driving me nuts.
Thanks a lot,
JT

 

someones gotta have some input on this? I just drove the car and it pulls pretty strong and has no surging of any sort at full throttle...tomorrow im going to disconnect the 02 sensors..if it runs smooth then I know its an 02 issue...anyone else have input? I just find it weird that a new GM 02 sensor could be shot.

 

If you want to rule out the extensions, I would pull them off and test them with a DMM for resistance.

 

Is there any way you can read your current data? Are the O2s not switching and lazy... lean or rich? Run a smoke test and check for exhaust leaks.

Grab some Auto Trans Fluid and pour 3 ounces into a running warm engine slowly. You should only see smoke at the exhaust tips. If it leaks at the header flange or y-gasket, then you found a leak that could affect your O2s.

 

Yea, I wouldn't be surprised if the header bolts backed out, they back out all the time and need to have a few cool doan cycles and tighten agian until they are sent home and locked. That would defininitly cause you an issue.

 

I was going to say the very same thing. Check for any exhaust leaks. Are your header bolts tightened? Good connection and tight at the collectors? Make sure there are no leaks.

 

Yep.

Remember to keep tightening the bolts after the first few heat cycles. Never torque bolts with warm heads... wait for the cool down.

 

I have already re-tightened the header bolts about 3 times. I also have new 02 extension wires on the way. I think today I am going to run the car with the 02's disconnected. If it runs smooth then I know for a fact its an 02 sensor or wire extenions issue.

 

Sounds like you are on the right track, you will get MIL illumination if you disconnect the O2s. Still check for exhaust leaks first.

 

I had a similar experience after my Hooker Longtube install.

I had alot of false knock to show up (I had a perfect tune with my hotcam kit and stock exhaust manifolds, and no knock anywhere)
The car ran faster with the stock exhaust manifolds???

I pulled 10 degrees timming across the whole timming map, and still had massive timming reductions due to False Knock. (did this to verify FALSE knock). I always run 93 oct fuel.

I relooked my header install looking for areas of frame contact, all clear...did find a couple spots between primary tubing bends that were very close, and close inspection found they were touching each other at some point..hard acelleration?? tubes resonating and touching??

Anyway I reprogrammed my good timming table back in and disabled my knock retard settings and no more problems!!

Also for your O2's reading lean bank 1, Hookers have that slip tube on cylinder #1 that can leak.

HTH
Keith H.

 

ok I just disconnected both 02 sensors. Walah, the car runs smoother than a civic:-) I have re-tightened all header bolts, and that first primary that is seperate is 100% sealed I made sure of this when I was installing the headers. So since the car running great with the 02 disconnected its gotta be either bad 02 extensions or I got a bad GM 02 sensor? does this sound like it makes sense?
Thanks

 

Is there any way you can read the Current Data? If you see the O2s cycling between .100 and .900 fast then they are fine. If they are lazy or stuck then those O2s are bad. No use replacing them without testing them.

Also, do what Shoebox said and run a resistance test with the O2 Extentions. A few dabs of Stabilant 22 really helps conduct electricity and can help with poor pin connections. You can get it at any VW store... they are notorious for connector problems.

 

ya, definatly sounds like something with the 02 sensors. good idea to check the 02 extentions. i doubt a brand new 02 sensor from GM would be bad, but u can check that too.

the wires run to the computer, but dont forget that the computer has to ground. check the ground connection off the computer!!!

one of my instructors had an 02 sensor problem, he took it to like 7 mechanics who couldnt find what was wrong. turned out - bad computer ground!

 

Where is the computer grounded at?
Thanks for the help guys.

 

get a wiring diagram for your car. that will tell you what color the ground wire for ur comp.

and i guarantee you'll use it again in the future