Hi guys,

Dumb broke kid here trying to fix my truck. I rented a scanner and got the codes:
po171
Solenoid circuit range/ performance bank 1 &

po174
Control solenoid circuit range/ performance bank 2

Under pending trouble codes it said the same thing. Where do I start to fix this??

I also notice a hiss under the hood when started and slowley fades out and stops when engin is turned off.

 

Hi Crismon and welcome to the forum

Diagnostic Trouble Codes (DTCs) P0171 bank 1 (Cylinder 1) and DTC P0174 bank 2 indicate the fuel/air ratio is too lean. The fuel trim system is at the rich correction limit.

I think it sounds like you've got a vacuum leak. What size engine do you have?
The most common thing lately is a split PCV hose. You can usually find a vacuum leak with a can of spray carb cleaner such as Carb Medic. With the engine idling you spray the carb cleaner at the different vacuum hoses etc. If the idle changes when you spray a hose or whatever youve found your leak.

 

I have a 6 banger. I will give it a try. Thanks a million.

Dave

 

You might want to try cleaning the Mass-Air meter too while your at it.
Jimmy

 

I spent the last few days working on my 171 and 174 problems. Tried going to the dealer for some advice, they "didn't trust the autozone codes" and would need to have a technician work on the car. I said thanks but no thanks.
I was sure it wasn't the PCV vaccum leak as I pulled the PCV valve and felt plenty of suck on it while the truck was running (97 F150 with 120K miles). I thought about the fuel filter thread but pulled the records from the last service a year ago and found I had the presence of mind to have it replaced. So I stopped myself on that. I really didn't want to spend the money on O2 sensors, so I tried the Mass Air Sensor by pulling the air filter housing and putting my finger over the hole where the sensor was, the trucks idle changed so i figured it was working.
Not beated down yet so I went back and read more threads and decided to go back to the rubber elbow from the PCV. I pulled the valve again, found lots of suck, and then followed the line (expecting it to lead to the rear of the intake manifold) and found it attached at the front of the manifold, under the main intake, in a horrible spot to work on. The elbow was bad, had an "eraser sized" hole it it.
Went back to auto zone, put something together with hoses and such, had my daughter (it is her truck and she has much smaller hands) put the thing together....went back to autozone, cleared the codes (free) and drove around for a half of an hour, no come backy....the codes I mean.

Thanks a lot for the help

john

 

Hey guys i need some help. I have a 98 F-150 and my check engine light stays on and i ran it on the scanner and it came up PO171 bank1 and PO174 bank2 were the problems but i dont kno what i can do about it to fix it. I changed both of my oxygen Sensors But its still not working. so does anybody have any advice for me? id really appreciate it

 

Welcome to the forum Redneck,
Read post #2,4, and 5. These are the most common reasons for those codes. Not the O2 sensors.
Good luck, hope this helps.

 

Look under the upper intake just behind the throttle body and you will see a rubber 90* elbow.It probably has a hole in it and thats your problem.

 

This code combo is NEVER due to faulty O2 sensors. It is almost always due to a vacuum leak. Occasionally, a dirty MAF will cause it.

Steve

 

hey fellas its me again...well i checked on all the things u guys said and i didnt find no holes in any of the hoses or anything could it be that i dont have the factory exhaust system on there? cause when i bout the truck not to long ago the guy had put a diff exhaust system on it and had flowmasters put on it? so could that be the problem?

 

Probably one of the reasons the big three are losing marketshare. What a scam, implying the codes have anything to do with Autozone. The dealer just wanted to charge you a $69.95 "diagnosis fee" for about one minute of work. The codes have nothing to do with Autozone. Those code numbers are generated by the Ford computer system on your truck.

The other suggestions regarding the PCV hose are valid. It's usually a vacuum leak that generates those codes. The PCV hose is a prime culprit. If replacing the hose doesn't solve the problem, check all the other vacuum hoses as well. If it isn't a hose it could be a leaky intake gasket.

 

jchipmaker was well within his rights to refuse the dealers offer and work on the problem himself. After all that is what the site is all about.

swingin.little.guitarman, I don't agree with you at all. This is no scam on the dealers part. The dealer doesn't have to offer advice to a customer. The dealer should not discount the information provided by jchipmaker but, the dealer was right in advising him that they would need to hook it up and read the codes themselves. If the job is given to them, they have to do this so that they know what they are working on and what service procedures are needed to correct the customers problem. If you were taking your truck to the dealer to have it fixed, would you expect anything less?

BTW, I am not a dealer technician or a dealer employee, just a everyday shade tree mechanic.

 

KRM,you are correct.When I had a CEL a few weeks ago I had AZ scan it.I then went to my local Ford dealer and requested a certain tech work on it,whom I knew.He said he still had to run a diag. on my engine,which cost $90.00! Anyway,he ran the diag.,replaced the IMRCs,and ran the diag. again to make sure everything was ok.....and he didn't charge me! See,sometimes Ford techs are good guys!