jpat1023

Ok so about a month ago I put on long tube headers and an ory, the few other mods I have are in my sig. Sometimes, about 30% of the time, when I accelerate at about half throttle the car pulls like expect until about 2800rpm and then for about 1 second it feels like someone hit the brakes. Once it gets to around 3000rpm the car pulls real hard until it switches gears, as expected. It is hard to reproduce, but when it happens it really does feel like someone tapped the brakes, like my body falls towards the steering wheel and everything because I am not expecting the car to stumble like that. I guess my question is, is this a tuning problem or what?? I am assuming it is since I have not gotten it tuned after the header install, but I was told the stock computer can handle headers? So what needs to be done to fix this?

98Grnz28

iTrader: (7)

Is the check engine light on???????? Sounds almost like an bad 02

jpat1023

No check engine light and I had the rear 02's tuned out...any other ideas guys?

LT1WS6TA

iTrader: (3)

mine does this exact same thing sometimes...cant make it do it when you want it to either. but just every now and then it will

jpat1023

Yea exactly...does anyone know what is causing this or how to fix it??

Jpr5690

iTrader: (13)

Sounds Like Kr... Is Their Any Audable Knock ? Also Mabye You Need To Change Your Plugs ? It Could Be A Misfire From Either A Bad Plug Or Bad Plug Wire....

jpat1023

Brand new plugs were put in during the headers install. And no I don't hear any knock. I really don't have any idea what is causing this.

robertbartsch

Same issue here. Check for a PO171 code.

Possible sources:
1. bad o2 - fronts
2. vacume leak manifold or MAF rubber clamp
3. Exhaust leak - head and collector
4. PCV leak
5. Injector O-ring leak
6. Bad electrical ground - PCM

RMR JAM

iTrader: (4)

My car was doing the same thing at 2500 rpm. I took the maf sensor off and it had a film on it. From what I read, if you have a oiled air filter (k&n), oil can get sucked off the filter and get on the wires on the maf. Cleaned it with electronics cleaner and now the stumble is gone. Not sure if that will fix anything with yours, but its a pretty simple thing to try.

jpat1023

Thank you robert and rmr. I am going to go over that little check list you made robert and I will clean the maf as well rmr. I will post back after this is done and let ya'll know if it solved the problem. btw, any other ideas are welcome, just in case i come back and still have a problem.

LT1WS6TA

iTrader: (3)

The K&N oil filter getting oil on my MAF is very possible....i will try cleaning it up.... and post back the results..what filters are you guys running to avoid the oil problems?? My Sig. didnt show up.. FYI my current car is a 99 Trans am

**Do Lt1 cars not have this problem?? I had a K&N on my 97 WS6 for 2 years and it never had a problem

robertbartsch

Same problem - I changed a bunch of stuff including:

1. Plugs,
2. O2s
3. Checke for vacume leaks, intake and exhaust
PVC leaks, etc.

,,,nothing worked until I swaped back the factory MAF - now the car runs great - no stumbling!