Code "33" MAF HELP!!!
Thread Starter
Racer
Joined: Sep 2002
Posts: 378
Likes: 0
From: Raleigh NC
Code "33" MAF HELP!!!
The TPI saga continues. Ever since I added TPI on my car I have always had a code 33 come up. It basically says the MAF sensor is seeing more than 45 grams per sec (2.2 volts or greater) of air moving through it at startup. I hooked it up to a scanner to read real time data during engine run. at idle it was only drawing about 6 grams/sec. The car runs fine and goes into closed loop but the check engine light is kinda annoying. Has anybody ever gotten this code before? Should I buy a new MAF?
~Christian
~Christian
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: Code "33" MAF HELP!!! (nitrocharger)
Lets narrow it down first...
Did you install a 52 or 58MM TB on the TPI?
Or was it the stock 48MM TB?
With the codes cleared from the ecm,Does the car start,idle fine,run fine and then once you drive it for a few minutes under load,is that when the code comes on and when it does,the car suffer in performance?
Just for reference,anytime you add/modify a TPI,add a larger TB,etc you will need to readjust the minimum air speed and set the TPS after.
If you didnt,you will get a code 33.
Sometimes,A larger TB on a MAF TPI car is notorious for throwing a code 33.YA gotta experiment with the min. air speed in increments and adjust the TPS until you find that no code sweet spot sometimes.
Other causes are to check the green wire for proper voltage,check connector for bad connection or breaks in contact,check MAF itself for bad contact in the plug hole,bad ecm or bad MAF sensor.Green wire may not apply if using a aftermarket harness that has its own colors.
Did you install a 52 or 58MM TB on the TPI?
Or was it the stock 48MM TB?
With the codes cleared from the ecm,Does the car start,idle fine,run fine and then once you drive it for a few minutes under load,is that when the code comes on and when it does,the car suffer in performance?
Just for reference,anytime you add/modify a TPI,add a larger TB,etc you will need to readjust the minimum air speed and set the TPS after.
If you didnt,you will get a code 33.
Sometimes,A larger TB on a MAF TPI car is notorious for throwing a code 33.YA gotta experiment with the min. air speed in increments and adjust the TPS until you find that no code sweet spot sometimes.
Other causes are to check the green wire for proper voltage,check connector for bad connection or breaks in contact,check MAF itself for bad contact in the plug hole,bad ecm or bad MAF sensor.Green wire may not apply if using a aftermarket harness that has its own colors.
Drifting
Joined: Apr 1999
Posts: 1,261
Likes: 6
From: Middletown New Jersey
Re: Code "33" MAF HELP!!! (nitrocharger)
What brand MAF are you using? I tried taking off my ported Bosch unit which wasn't throwing codes and tried a Wells MAF. I replaced both relays also. I couldn't keep the Wells on because I kept getting code 33. If you have acces to a different MAF, I would try it.
Interestingly, when I turn the key to on without turning over the motor, the I get a reading of around 24 gm/s. When I start the motor, it reads about 9 gm/s at idle. I haven't figured that one out myself yet.
Interestingly, when I turn the key to on without turning over the motor, the I get a reading of around 24 gm/s. When I start the motor, it reads about 9 gm/s at idle. I haven't figured that one out myself yet.
Team Owner
Joined: Mar 1999
Posts: 89,144
Likes: 3
From: Life's tough, wear a helmet.
Re: Code "33" MAF HELP!!! (nitrocharger)
Check the reading via the scanner but also check it right at the sensor. If they don't match your ECM is likely the problem.
I had a similar issue a couple years back. Turned out that my ECM was bad and was just making stuff up, not actually using the readings from the sensors themselves.
I had a similar issue a couple years back. Turned out that my ECM was bad and was just making stuff up, not actually using the readings from the sensors themselves.
Thread Starter
Racer
Joined: Sep 2002
Posts: 378
Likes: 0
From: Raleigh NC
Re: Code "33" MAF HELP!!! (nitrocharger)
Alright i fixed the problem, kinda. I ended up switching the relays (MAF power and MAF burnoff) and the code went away. Im not sure why another code isnt generated if the relay is bad on the MAF power but it seems ok. I dont know why both relays seem to work in one configuration and not another? I'm going back to the carbed C3 boys on the forum but really appreciate the help from you C4 guys.
~Christian "my car is smarter than I am" Crew
~Christian "my car is smarter than I am" Crew
Pro
Joined: Jul 2001
Posts: 557
Likes: 0
From: Taxahoma
Re: Code "33" MAF HELP!!! (nitrocharger)
Unless it was a bad connection at the relay switching them may still pop the code up sometimes. If it pops up again I'd swap them both out. Just swaping them worked for me a couple days and had to end up swapping them both out completey.
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