My factory standard 1989 305ci trans am is giving me a headache with this code 33. It started a month or so ago by intermitantly from cold startting then stalling withing a few seconds it would do this 4 or 5 times then run fine. I have swopped the Maf over from a working camaro one but made no improvement. I swoped the maf relays around and setup the IAC and set tps to 0.54volts. I followed the GM diagnostics info from the boards and the wiring all checks out fine. Sorry my first post is asking for help but I sure am stuck on this one . Any idea what to check next could it be a faulty ecu or anything else. Mike from u.k

I once had a bad ECM that was frying every new MAF sensor I put in it.

But in all seriousness, if the car is running fine other than a light coming on on your dash, it's no big deal. If it's coming on continuously and hurting performance then there's a problem. Sometimes I will be cruising down the freeway at night time and the MAF will throw 33 with no sign of any lack of performance or anything. And then it will not come on for months after.

I read once, even, in my service manual that given the right parameters... temperature and throttle at 25%, for the right duration of time... the MAF can throw 33 even if there is no issue whatsoever. It's a fluke, a design flaw. A little known fact. Having wrestled with this issue for a year on end (back then), checking and replacing almost everything related to the MAF system, knowing it in and out... take my advice and just let it go if its not hurting your performance or hindering your progress in any way. It's not worth the headache or the money.

cheers for the reply
Yeah the light is on all the time within a few seconds from starting it comes on and I noticed the electric fan is running even with the engine at a low temp which it didnt do before.

It`s not running too bad but It uses more more fuel with the light on infact it`s using more than my old 350 gta used to use which is strange.

yeah think I will take your advice headache`s I got and money I aint so may just take the bulb out and forget about it.

If you have the 33 error code, the ECM should go into "limp home mode". On my car, with the 33 error code, the car would barely run at slow speed. You can erase the 33 error code by disconnecting the negatve battery lead for 1 minute. Doing this will reset the ECM.

You should do a search on this matter, tons of stuff has been written.

You set the 33 error code if the following three items are true for one second of duration:
1) The ECM "sees" 45 gms/sec from the MAF,
2) TPS is less than 25%, and
3) RPM is less than 2000.

It is very unusual for a 305 is pass all three items at the same time. 350s can do it often. I was plagued with the 33 error code also, after modifing the engine. After swapping out relays and playing with the TPS settings, the only way that i could get rid of the 33 error code was to learn to program my own Eproms.

However, I did learn to get onto the expressway by using D on the tranny. Once up to speed, then change to OD. Keeping the tranny in D will keep the RPM over 2000 before the MAF will report 45 gms/sec. Kinda of slick!!!

Yes I have done a lot of searching on here but still cant find an answer that fixes it

I have owned the car for under a year but in the time I have had it its only just started in the last few months showing the error. The car runs very well at the moment with no starting problems at all, If the light wasnt on you would never no it had a problem.
will running it in limp home mode cause any damage ?
Would a ALDU1 Xtreme aldl from Moates.net be any use in helping me track down the fault ?