Well I don't have a coil pack code...so I dunno if that would help me. I'll keep that in mind though. I'll try the injectors first.

Swapping them should take about 15min at most and worth a shot before you decide to take apart the UIM to get to the fuel rail. Those where the only two engine codes I had at the time.

I don't have a coilpack problem...so what would switching them do for me?

Try checking for leaks around your EGR on the intake manifold and the pipe that connects to the exhaust. It might be tight but not seated properly. And try cleaning your EGR and TB while you at it.

Do you still have an exhaust leak even after swapping to the FED spec manifold and new y-pipe gaskets? Exhaust leaks can cause leaning!!!!

hmm you know, I do hear a hiss behind the intake manifold, maybe theres a leak but i was thinking it was just the tb sucking air making that noise, ill have to investigate further but when its 20F and 500Mph winds you kinda dont want too.

So I installed a new O2 sensor (preventive maintenance but figured I might give it a try and see if it helps) and it didn't fix the problem.

I then got tested but used injectors and installed those today.

Car runs MUCH better and is much smoother during acceleration throughout the RPM range. Also, after 60 miles...not even a pending code has come up.

I'm hoping I have fixed the problem.

You unplug all coils one at a time while running to see if one makes no difference. But mine shook REAL bad when a injector was bad.

That's for coils.

Injector checking is different since 3 of them aren't always accessible.

But anyway...I think I fixed my problem so no need to do anything (I hope).

Iam still getting the same code, checked egr and related parts, , only other thing i can think of is FPR

Yeah the injectors didn't fix the problem for it me. It came back.

Im getting stink overheated cat smell now also so i know she is running lean, hope i dont toss a rod lol

Another update.

I changed my engine coolant temperature sensor and I was able to get the car inspected just fine. Who knows...maybe the code is fixed now. Drove 50 miles and there isn't even a pending code.

Hmm ill have to look into that one.

Well the light came back on yesterday. 2 weeks after 'fixing it'. Don't know if it's cause I went WOT for the first time or because it's warmer? Whatever it is, car is running lean 'again'.

I had the PO171 lean bank 1, code on my lexus rx300 over the wknd. Basically bank 1 is getting too much air. On that cars forum it said it 's the MAF sensor 80% of the time, then faulty 02 sensor, then other various reasons. I didn't think it was the MAF cause that would affect both banks not just bank one. So I decided to clean bank 1's TB. This car has 1 TB for each bank. Anyway cleaned both TB's, just had some soot around the bottom of the butterfly valve, which just might have kept the valve from closing all the way @ idle. Anyway, disconnected and charged the battery while cleaning, and my wife has driven about 40 miles with no CEL. But maybe it's too soon to tell. next step will be the 02 sensor but they actually call them, air fuel ratio sensors @ about $200 ea. ... Good Luck.

did you try seafom?

Yeah I did it after first getting the 00VI.

I have another MAF to try. I'm also going to try grounding it.

just a folo up, my wife has driven over 500 mi, and the PO171 code never came back.

folo up #2., P0171 cel came back after 2000 miles. Cleaned the cars'
maf sensor, was a bit dirty (1st time in 110k miles). Checked for leaks, cleared the code and will see what happens. . Already bought the air/fuel sensor for the next step.

My issue was a vacuum leak. Once I put the stock IM back on everything was fine. Either that or my fuel rail was screwed up. I'm still convinced my 00VI was leaking air somewhere.

I am un-subscribing from this thread. Good luck to any of you with this issue in the future. I fixed it by leaving/returning my engine to stock.

I found the cause to my codes finally ! ! ! , Vacuum Leak! It was the PCV Valve grommet......, I temporarly capped of the vacuum line to it and its a night a day diff, I have a crap load of power again, No more pinging and no more SES light !!!

It could possibly be the injector seals. I am also guessing you used brand new intake gaskets? I am working on a mitsubishi with bank 1 and 2 fuel trim malfunction. No one can figure out why. We replaced. intake gaskets (U & L), Tune up, PCV, MAF, Cleaned EGR ports, replaced EGR. Checked Timing, just about everything, and the codes are still there... im ready to blow the ***** up.. that will solve all the cars problems

injector seals are good, i never removed the intake so no need for a gasket, however i had the VIAS out and i may have goofed up that gasket, but so far so good, pulls hard again and no pinging at 2k rpm like a diesel engine. even on 93 octane