when i first started it up sunday i let it get to full temp sitting in my driveway and when i started driving it it was stumbling noticably. than i changed the o2 sensor and reset the computer and drove around for about 12 mile last night with no problems.

this morning it started stumbling after the car was warm and i had been driving for a few miles (like 3-4). thats when i took off and reinstalled the intake manifold and headers and ypipe to make sure there were no leaks.

since then it has done the same exact thing twice

when cold, the car stumbles really bad, but after driving for about 2-3 minutes (like 1-2 miles) and the coolant temp at around 160-190 (stock temp gauge so dont really know)it drives fine. it idles fine and runs fine at WOT. it did this when i first ran it after redoing the intake and exhuast. than i let it cool down fully for about 6 hours and it did it again when i drove it around after work. ran like crap for a few minutes when the engine was cold, but ran fine once it warmed up. still no SES light yet today though.

 

Do you still have these problems????

This is exactly what my car is doing.

It seems like an open -> closed loop problem.

Just replaced the o2's and it still does the crap.

 

Do you have and A/F gauge on that sencer i did and had the same problem. Also check to see if all you 02's are tight and if you plugs are also tight.

 

Tally, my car also throws the insufficient switching code.
Remember how I need to let the car warm up before driving, or else it sputters? Similar eh? It's gotta be the switching. Gotta be tuneable.

 

sounds like loose connection electrically somewhere.intermittent problems like you have usually are that or a wire grounded out somewhere. sorry i can't be more specific.

 

holy **** this thread is like 4 months old

problem has been fixed, four like 3.5 months

turned out the connectors for the o2 sensors was all dirty with coolant so i had to take it apart and clean it

 

I've had a few of my threads exhumed from the dead also. Glad to hear the problem was fixed.

 

Cool thanks for giving me something to look for. My car has been doing this since I put the new engine in. I need to swap the rear o2's with the fronts and clean out the connectors, hopefully that fixes the surging promblems.
Glad this post was resurrected
J

 

hah... cool.
If the new O2 didnt fix it... i'll start cleanin sensor connectors.
Replaced the drivers side with a vette O2 sensor... thats a LONG harness. I cleared the computer tonight and it drove home fine. We'll see tomorrow during the day since it seems like it only happens during warmer weather.
At least I resurrected a good post.

 

Yeah you did. I just finished my install today and didn't want to get on it. After 40 miles I stepped on it to about 3500 rpm and felt it stumbling like when you arm a wet kit but leave the nitrous bottle closed. I will inspect closely tomorrow and drive it a bit more that is if I don't drop a seat (guess what heads I went with ).

Gilbert