My IROC pops code 33s, but only when it's cold. It's not a TPS adjustment, because the car stumbles BADLY right before the light comes on. If it gets up into the high 40s or 50s, it goes away. The colder it gets, the more often I get the stumble and the code. Anybody have any ideas? All I can imagine is that the circuitry on the MAF (I'm running a Wells SU 145) flakes out in the cold.

 

I have the wells unit and I'm getting code 33s but it's done that since I got it. Did you resolve this issue????

 

my car does the same thing, and only when the engine is cold. it started about 2 months ago. i have a reman bosch maf im pretty sure, but it is a couple of years old. i have checked all wiring and plugs and pins and its not a loose connection, i even checked at the ecm.
the other day i unplugged the relay by the brake booster labeled "maf power" and stared the car i got a code 33 after only 5 seconds. so i think the problem is with the relay.
normally (with the relay in place) i can drive the car for between 2 and 10 minutes before the code occurs but it happens every time, code 33.
after the car gets up to temp with the SES light on i can shut the car off for 15 min and start it up again and the light stays off and the code does not return again until the car is parked long enough for coolant tem to get to below 100.
i have a maf power relay on the way. after i replace it i will let you know.

 

Yeah, I fixed the problem by putting the car away for the winter. I'll take it out when it's warm.

The heater core exploded a few weeks ago and I'm too irritated to deal with it so I just put the car away.

But, just to keep me company, my GTA decided to start spouting MAF codes now.

I swear I'm selling every fricking car I've got and buying 1 with a warranty.

 

I just replaced the maf power relay yesterday. after i replaced it driveability was much better and the code did not re-appear, but i did get a code 36 every time i restarted the car after that so i replaced the burnoff relay. reset ecm. car runs great and no codes. hope this helps when you take the car out of storage this spring.