Power drops at around 5k rpms, is MAF bad?

[thewraith]

When driving my car- it pulls strong all the way till about 5k rpms. At that point there is a noticeable reduction in power. I do have cel on for running lean in a cylinder (maf issue after k&n install). Does the engine hold back timing/fuel w/cel on? I am waiting on a replacement maf sensor right now. I also have a question about diagnosing a bad maf:

When my maf is installed and hooked up, the car holds idle fine (maybe a 200rpm fluctuation). However when I remove the connection for the maf- the car will not idle properly. Is my MAF still bad or should I see this as a sign there is another issue?

thanks!

meek

[Loren]

What are your fault code(s)?

[win911]

Would help if you tell us the code you are having?

[wwest]

When driving my car- it pulls strong all the way till about 5k rpms. At that point there is a noticeable reduction in power. I do have cel on for running lean in a cylinder (maf issue after k&n install).

Does the engine hold back timing/fuel w/cel on?

Depend on it, YES..!!

I am waiting on a replacement maf sensor right now.

Toss the K&N first, otherwise you will be wasting money on the new MAF/IAT.

I also have a question about diagnosing a bad maf:

For most cars if you start the car with the MAf/IAT disconnected you will get a CEL but the idle will be okay. Idle or constant speed cruising does not rely on the MAF/IAT functionality, only the upstream A/F mixture control oxygen sensor(s).

On the other hand disconnect the MAF/IAT(***) with the engine idling, get a CEL, and the engine will either die or idle poorly.

For many this is a simple way to temporarily disable PSM(VSC)/TC. When there is a CEL many vehicles disable these functions.

When my maf is installed and hooked up, the car holds idle fine (maybe a 200rpm fluctuation). However when I remove the connection for the maf- the car will not idle properly. Is my MAF still bad or should I see this as a sign there is another issue?

thanks!

meek

[thewraith]

When driving my car- it pulls strong all the way till about 5k rpms. At that point there is a noticeable reduction in power. I do have cel on for running lean in a cylinder (maf issue after k&n install).

Does the engine hold back timing/fuel w/cel on?

Depend on it, YES..!!

I am waiting on a replacement maf sensor right now.

Toss the K&N first, otherwise you will be wasting money on the new MAF/IAT.

I also have a question about diagnosing a bad maf:

For most cars if you start the car with the MAf/IAT disconnected you will get a CEL but the idle will be okay. Idle or constant speed cruising does not rely on the MAF/IAT functionality, only the upstream A/F mixture control oxygen sensor(s).

On the other hand disconnect the MAF/IAT(***) with the engine idling, get a CEL, and the engine will either die or idle poorly.

For many this is a simple way to temporarily disable PSM(VSC)/TC. When there is a CEL many vehicles disable these functions.

When my maf is installed and hooked up, the car holds idle fine (maybe a 200rpm fluctuation). However when I remove the connection for the maf- the car will not idle properly. Is my MAF still bad or should I see this as a sign there is another issue?

thanks!

meek

Ahhh crap, search is my friend!

[thewraith]

The CEL codes are 1123 and 1125, looks like a bad maf sensor. Waiting for it to come in, hope this is the cause. I DID break the two hard plastic lines that go to a sensor right above the alternator (evap?). Can anyone tell me what these are for? I band-aid solutioned them by running hose from one broken piece to another in hope that it would fix my issue.

thanks again

meek

[nick49]

I have the same symptoms and the same codes with cel on. I replaced my MAF and turned the CEL off. It came on again the same day. My car is a '99. Any ideas?

[Loren]

I have the same symptoms and the same codes with cel on. I replaced my MAF and turned the CEL off. It came on again the same day. My car is a '99. Any ideas?

You need to read your fault code(s).