So after the seafoam treatment(1 can induction clean, 1 can in the tank), changing the wires and plugs, and running through a full tank of gas, it now has 2 pending codes. P0171 and P0174. I also noticed some weirdness with shifting from 3rd to 4th.

Forum searches seem to point to the MAF but I noticed a crack in the Y-Pipe under the Header connection on the Driver's side. Could that cause one of the codes?

Santa brought me an UltraGauge for christmas. Is there anything I can monitor to get a better idea of where the problem is?

 

Check and make sure the o-ring between the MAF and the filter lid is not broken, missing or torn.
Be real careful around possibly cleaning the MAF. If you want some help with this, send me your number and I'll call you.

 

Replaced the broken filter lid and o-ring already.

 

Air leaks on the air side of things would be more likely (MAF hose, etc.). System is sensetive to "un-metered" air flow, like a vac leak. Codes will usually move from pending to Light the CEL/MIL on two drive cycles. See attached from Bosch guide to the ECU system

 

What constitutes a drive cycle? The codes haven't moved to light the CEL yet.

Another hopefully quick update. I was looking at the the various hoses going to the intake to get an idea of the clamp sizes I need to replace the old clamps and noticed the clamp on the breather hose on the right side was loose. Could that be causing the codes?

I still plan on replacing all the clamps on the left breather hose and the idle air controller to rule out any of those leaking. The hoses look good but the clamps have been removed a few times so they may not be as tight as they could be.

 

A drive cycle is about 400 miles of driving, drive 400+ miles with no faults present and the check engine light should go out.
If you need to get it inspected until you have driven the 400+ miles the OBD system will read "not ready" and you will fail inspection.

 

Replaced the hose clamps on all breathers and the idle air controller. Drove it a lot this weekend and was blessed with a few pending codes: P0174 P0171 P1175 P1172

Signs are pointing to the MAF. I have noticed some weird shifting from 3rd to 4th but have yet to see the P0734 pop up. When I bought it, the air box clips were broke so I'm not sure how long the PO was driving around with it that way. When replacing the air filter and air box lid, I noticed a bug plastered to the MAF grate so I don't have much confidence that the MAF is as clean as it should be.

Unless anyone else has any ideas, I'm going to order a MAF.

 

Just wanted to update some things I did in attempting to stop the codes.

Had the y-pipe exhaust flange cracks welded up. Turns out both sides had cracks and were leaking. Sounds better now but codes were still triggered.

I also ordered a new Bosch MAF from partsbin.com and installed it last night. Runs much smoother now. Cleared the codes. I would be surprised if the codes come back.