[DWilliam]

2002 with 140k. No symptoms, but it has the codes above. So far I’ve done:

Fuel pump, check valve, plugs, wires, coil on cylinder 1, timing belt, water pump, thermostat, VSV valves. Cleaned MAF sensor and throttle body.

I plan on doing the hose leak test with carb cleaner to see if I can trace a vacuum leak. Is there anything else I should look for? I assumed the misfire on 1 was a bad coil so that’s why I did the plugs, wires, and replaced that coil. Truck seems to run fine and doesn’t have any issues.

[19963.4lsr5]

The P300 is random multiple missfires. Probably from the P171 system too lean code. Look for cracks in the rubber intake trunk.

What is your warmed up idle rpm?

What is your MAF reading with a warmed up idle?

How old is your fuel filter?

Any exhaust leaks?


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[DWilliam]

Originally Posted by 19963.4lsr5

The P300 is random multiple missfires. Probably from the P171 system too lean code. Look for cracks in the rubber intake trunk.

What is your warmed up idle rpm?

What is your MAF reading with a warmed up idle?

How old is your fuel filter?

Any exhaust leaks?


Sent from my iPhone using Tapatalk

Getting around to updating this. MAF sensor and throttle body were cleaned. Coil replaced on cylinder 1. All new plugs and wires. Still have the codes. My reader says MAF is 0.50 lb/min and fuel rate is 0.33 gal/hr at idle

The big black hose that the MAF sensor is on is looking a little old, do you know the part number for that? The one that also hooks to the throttle body.

Anything else I can troubleshoot with this? I just want the damn CEL off. I’ve put 10 grand into this thing in less than a year.

[Texmax]

Originally Posted by DWilliam

Getting around to updating this. MAF sensor and throttle body were cleaned. Coil replaced on cylinder 1. All new plugs and wires. Still have the codes. My reader says MAF is 0.50 lb/min and fuel rate is 0.33 gal/hr at idle

The big black hose that the MAF sensor is on is looking a little old, do you know the part number for that? The one that also hooks to the throttle body.

Anything else I can troubleshoot with this? I just want the damn CEL off. I’ve put 10 grand into this thing in less than a year.

Did you pull the throttle body off to clean it? if yes, gasket is in upside down. If no, get a smoke machine.

[jgue467]

Originally Posted by DWilliam

...
The big black hose that the MAF sensor is on is looking a little old, do you know the part number for that? The one that also hooks to the throttle body...

This solved my 0171 - pic of part num. attached-Luck.

[jgue467]

Originally Posted by jgue467

This solved my 0171 - pic of part num. attached-Luck.

Oops here it is.

[DWilliam]

Originally Posted by jgue467

Oops here it is.

Thanks! It’s available on Amazon for 12 bucks, or OEM is about 65 after shipping. I normally always go with OEM, but is this something I can go cheaper on? It just seems like a plastic hose.