1996 Sierra can’t get rid of MAF code

[zakkb787]

5.7l has 2 cats and 4 O2's, 5.0l has 1 cat but 3 O2 sensor. Swapping upstream O2 sensors is not fun as GM buried the passenger side upstream O2 sensor plug up beside the exhaust manifold inside of a heat shield. If you have big hands(like me), forget getting to the plug with your hands. I used my long needle nose pliers to release the plug and get it released. It always seemed to be the 1 that failed and would wreak havoc. I hated those obd system's, I lost track of how many goose chases I went on working on them. Getting cylinder misfire codes that ended up being an O2 sensor, cylinder #4 misfire codes for failed knock sensors, downstream O2 sensor codes from leaking intake gaskets, spider injection setting too many codes to list, and so on.

Hmm sounds like it needs to go on Craigslist

 

[02greysixer]

Having the same issue with my little 95 Tacoma. Can't keep that stupid light off from either a p0401 egr code or p0420 catalyst efficiency code. It's obd2 but very dumb and I can't view anything.

My fix is going to be a 4.8 or 5.3 swap soon as I find a deal on one or blow up the tapping 3.4.

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[Chevy1925]

Having the same issue with my little 95 Tacoma. Can't keep that stupid light off from either a p0401 egr code or p0420 catalyst efficiency code. It's obd2 but very dumb and I can't view anything.

My fix is going to be a 4.8 or 5.3 swap soon as I find a deal on one or blow up the tapping 3.4.

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if there is ANY exhaust leaks (manifold, joints, etc), toyotas will throw those codes.

 

[02greysixer]

if there is ANY exhaust leaks (manifold, joints, etc), toyotas will throw those codes.

I don't hear or see any. I'll have to go over it again. I've only put a couple hundred miles on it since doing heads. I got it with a very blown head gasket.

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[Chevy1925]

I don't hear or see any. I'll have to go over it again. I've only put a couple hundred miles on it since doing heads. I got it with a very blown head gasket.

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exhaust manifolds are common to crack as well as bad gaskets at the headers to exhaust pipe. they are touchy SOB's