MAF sensor High and Low? (code 33 and 34)
Thread Starter
Cruising
Joined: Nov 2006
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From: Orlando Florida
MAF sensor High and Low? (code 33 and 34)
I've had the check engine light come on periodically lately and when I checked it, it gave me the code 33 and code 34 which are MAF sensor high and MAF sensor low. How can it be both?
Le Mans Master
Joined: Aug 2007
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From: WV
This tells you what to look for on each of the codes. Since both say to check the wiring and connections that is what I would check first. You could also just have a bad maf sensor or a bad power relay.....WW
Code 33 (1985-1990) Inspect intake system for leaks, Inspect for vacuum leaks, Check MAF connector and wiring, Check MAF for open using digital Ohm meter. Possible ECM failure.
Code 34 (1985-1990) Clean the throttle body. Check MAF connections. Replace MAF relay. Replace MAF Sensor. Possible ECM failure.
Code 33 (1985-1990) Inspect intake system for leaks, Inspect for vacuum leaks, Check MAF connector and wiring, Check MAF for open using digital Ohm meter. Possible ECM failure.
Code 34 (1985-1990) Clean the throttle body. Check MAF connections. Replace MAF relay. Replace MAF Sensor. Possible ECM failure.
Burning Brakes
Joined: Mar 2010
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[QUOTE=WW7;1576418176]This tells you what to look for on each of the codes. Since both say to check the wiring and connections that is what I would check first. You could also just have a bad maf sensor or a bad power relay.....WW
Check your wiring and connections before you start replacing switches. All of my MAF issues were from a grounded wire in one of the relay harnesses.
Check your wiring and connections before you start replacing switches. All of my MAF issues were from a grounded wire in one of the relay harnesses.
Burning Brakes
Joined: Jul 2010
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From: When Democracy becomes tyranny, the armed citizens will still get to vote!
Might also want to clear out the codes to make sure that you aren't chasing a problem that only exists int the ECM's memory of days gone by.
5th Gear
Joined: Sep 2010
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Have you pinned this down? I've had the same two codes coming up. I replaced the MAF sensor and both relays. I've also gone through the wiring and can't pinpoint a problem. I'm thinking of replacing the ECM next. I'm curious to hear what you discovered...
One interesting thing I noticed is that a new MAF sensor seemed to take care of the problem for a few weeks. Then the codes started showing up again. I also have noticed that once the engine warms up and I shut the car off and restart it, the check engine light stays off and it runs better with no codes.
I haven't tried cleaning the throttle body. I guess I'll try that before replacing the ECM.
One interesting thing I noticed is that a new MAF sensor seemed to take care of the problem for a few weeks. Then the codes started showing up again. I also have noticed that once the engine warms up and I shut the car off and restart it, the check engine light stays off and it runs better with no codes.
I haven't tried cleaning the throttle body. I guess I'll try that before replacing the ECM.
