Code 33 causes
Thread Starter
Burning Brakes
Joined: Dec 2012
Posts: 788
Likes: 160
From: Rio Rico, AZ
Code 33 causes
Was driving two days ago and the engine in my 1989 sputtered for three or four seconds then the check engine light came on. The engine smoothed back out and I continued my drive for over an hour. Once home I checked for codes and it was "33". I had a nearly new MAF on my work bench so I swapped it in. I drove some yesterday, no problem. Today, about an hour ago the engine missed for a couple seconds again but smoothed back out and set a code "33" with this MAF sensor. I'm going to look at my service manual...but does anyone have some suggestions? I realize the "newer" MAF might be bad but it's only about 10 months old.
Thanks, Went
Thanks, Went
Last edited by Went; Dec 2, 2020 at 08:17 PM.
Melting Slicks
Joined: Jan 2014
Posts: 2,193
Likes: 381
From: Lunenburg MA
Code 33 is set when the ECM sees a high air flow at less than 1/4 throttle or at less than 2000 RPM. The MAF relay may be dropping out or the TPS may have a bad spot. I would check your throttle position sensor resistance across the full range (idle to WOT). It may have an open spot which is confusing the ECM. The service manual has the full test procedure for the code.
Melting Slicks
Joined: Aug 2003
Posts: 3,418
Likes: 406
From: Lakeville MI
A modified engine may simply be exceeding the 45 gm/sec threshold within the given rpm and tps constraints. This is often overlooked, but can be addressed in the tune if necessary.
Last edited by tequilaboy; Dec 3, 2020 at 01:10 PM.
