Hi all, what could be causing these codes? They are the only codes I'm throwing, and I also have a high, unsteady idle. Truck stumbles sometimes under acceleration, and CEL only comes on intermittently for a short period, but always a few times per drive.
When I disconnect my Iac, idle doesn't drop. When I disconnect my MAF, engine dies. I can not detect any vacuum leaks via starter fluid or cigar method. Have already cleaned but not replaced MAF. Spark plugs look lean. Also replaced FPR, pressure was and is still a little on the low side at 28 psi. Also replaced my TPS and Camshaft position synchro, both of which I had codes for and only codes left are the 172,173,176,177. Anyone got ideas? Thank you

 

Bump
Nobody has any help?

 

1st off

replace the rubber hose elbow from the intake manifold to the brake master cylinder booster

they are the 1st vacuum hose to leak

have you ever replaced the spark plug wires and the ignition coil pack
if not DO IT!!!

 

Thanks for the reply
When I first bought the truck I noticed that the rubber grommet which that hose goes into had some cracks and would leak if I moved it around, but autozone didn't have a similar one so I temporarily fixed it with silicone. Do you know where I can find a new grommet?

Also, the coil pack and spark plug wires look like they were replaced but not by me so I can go ahead and do that. Would that really be causing a fuel/air mixture fluctuation though?

 

new grommet would be dealership only

failing spark plug wires and or coil pack failing would cause check engine light to illuminate

my coil pack was only 4 years old and was failing already

a failing coil pack will emit heavy EMI which interferes with the computer sensors , sending false signals and also messes with the engine computer itself

 

I'm going to order coil pack, wires, grommet, maf sensor and intake gasket set. Not sure what the issue could be besides one of those things.

 

when my coil pack was failing , random dash lights would come on then off

the dealership found zero codes stored on the engine computer

do not go with motorcraft wires go with MSD or even better go with GRANATELLI

the best spark plug wires you can get