Hey guys,
I just started to have this problem yesterday. Engine light comes on and stays on. Engine shakes and truck won't go over 50 MPH. Autozone code checker came up with P0171.

Truck has about 95K miles and I had the spark plugs replaced at 75K miles.
Transmission was rebuilt at around that time also.

I only drove it to Autozone and back today to post the code and see what everyone's opinion is as to what's wrong.

Here's what the printout says:

P0171
"Fuel Trim Bank One Condition"

I'd appreciate your input.

 

This code is for a lean condition on bank one. It's most likely an injector problem or a vacuum leak. One causes not enough fuel, the other too much air.

 

Thanks, would have any guesses as to the cost to repair each?

 

Can't help on the cost. Whatever your local mechanic charges for troubleshooting and parts.

 

Finally got the truck fixed. It was a bad plug, COP, and gunked out MAF.
While it was at the dealer, I had the coolant flushed, and rear diff done with synthetic.
They also cleaned fuel injectors, intake manifold ports, intake valves and combustion chamber.
It has been years since these maintenance items were done so I hope it will be good for a while.
Truck just turned ten years old and I still love it!

 

I'm curious--how were your mpgs and smog test results before this? Any unusual behavior earlier?

 

Yes, engine had started getting sluggish and had unusual vibration. According to the inspection station, it just barely passed the last check.