So I just picked my car up from service. My CE light was a P170 fuel trim code. They don't know what caused it, but the tech at SOA that I talked to on the phone recommended:
1) STOP using 93 octane fuel. The motor does not create the BTU neccessary to burn it off creating carbon deposits.
2) Adding the air filter to the second air box. Us non-CA '99 cars don't have it but SOA now recommends putting it in.
3) Get a top-engine clean to remove carbon from the valves, injectors, etc.
They still charged me the $89 diagnostic fee even though I have an extended warranty. They said nothing was mechanically wrong and no parts were replaced so I had to pay.

What do you think?

Chad:cool:

Man, you're dealer really sucks.

I've never ever heard that using gas with an octane level higher than recommended could ever lead to a fuel trim problem. If you're getting excessive carbon buildup, it's probably the result of the Fuel Trim Malfunction, not the cause. What they should have done after finding a Fuel Trim Malfunction code was:

1) Check the exhaust system for holes or loose bolts
2) Check the air intake system for holes loose bolts or poorly-connected hoses
3) Check the fuel pressure (both with and without the pressure regulator vacuum hose connected)
4) Check the engine coolant temperature sensor
5) Check the MAF/MAP sensor (whatever it is on the 99 Impreza).

If none of these checks uncover the problem, then they probably need to call SOA.

Ask the tech to read to you the Diagnostic Procedure for your Fuel Trim Malfunction code from the Subaru Service Manual and then ask the tech to follow that procedure.

Chad,
for what it's worth, I had to pay $150 to get a code pulled on my talon one time.

They should have done it under warrentee. Next time I would go to another dealer, but hopefully there won't be a next time.

I've repaired too many of these to count. Have them replace the air flow meter, no more problems. The airflow meter was problematic for the 99 MY--very common for these to cause that code. Hope this helps!!! E-mail me if you need any other help.

Bret Carter
Subaru Senior Master Tech
Flatirons Subaru--Boulder, CO

Oh I forgot they also said my Platimun plugs could be causing a problem. What?? Thanks for the tips, but what is the easiest way to tell them how to do their job? They're not just gonna replace the MAF because I ask them to.

CHad:cool:

Should I call SOA and try and get my money back? I've never had a problem like this. How should I handle it?

Chad

Okay check this out! So I just called SOA and talked to a nice nice man named Ray. He is reimbursing me the $89 diag. fee as a goodwill gesture b/c of my ext. warr. He also started a case # for me so if I have future problems with a fuel trim malfunction, I can report it to them and there will be a record beyond the idiotic local service center. That's my first dealing directly with SOA and I have to give them a pat on the back. It took me a total of less than 5 minutes to talk to someone and get them to make things right.
Thanks again for everyone's help. If the light comes on again, I'm gonna use STiShawns spare MAF and see if the problem seases. I'll keep you all posted.

Chad, what dealer was this? The RS comes with NGK Platinum plugs off the manufacturing line from what I hear! I've seen them sitting in the dealer too, all boxed up in the Subaru parts box with NGK Platinum on them.

Joel - It was Fusz. I don't know about your 2000, but my '99 had Champion weed wacker plugs.:p
I just finished writing a letter to the service manager at the dealership so if this crap happens again, he can't say he wasn't aware.

Chad:cool:

Firstly, I would like to say thanks, for the welcome to this board. It really helps to know people that have some knowledge og the car, as this is the first AWD & Turbo vehicle that I have EVER owned.

Getting to the business, though, I also had a check engine light come on, two days after I picked my new wagon up, from the dealer. I was driving to work, and could only think, "OH fugg" here I go again. I just got out of a "lemon" with my '01 stratus R/T, and after getting all my money back, I decided to get a WRX wagon.

Then, I went to the closest dealer, who is relatively close to work, and they told me that the computer read out a code of p1443. This has something to do with the evaporator within the emissions system.

Needless to say, I went to the dealer where I bought the car, and nearly cussed them out, for selling me a car that has issues, considering they knew the situation that I had with the '01 R/T. Nice car, just that it was a lemon...went thru 3 NEW tranny's, all new suspension components, and finally, 2 court cases, and I won!:D

They finally have the computer back from SoA today, so let's see what happens. The car has been with me for 4 days, and in the shop for 5. geez...I hope I am not in the same bind again.

Anyone have any suggestions? Would be much appreciated.

phatride01. (I should have changed it to 02, but that's all good).

Well, dunno bout plugs in the 02's, but my 01, though NGKs are OEM replacements, the factory puts in Champions. =P I just swapped mine out yersterday for NGKs.