id run some sea foam thru the vacuum hose on your brake booster with the car running. its only a couple bucks and cant really hurt to try. all the directions are on the bottle. personally i didnt use enough to make white smoke come out of the tailpipe. i just used what the bottle said.

Thanks Jason, I'll try that.

Tried the Sea Foam, and it didn't work. Taking it to the mechanic, and see what he says. Will post what'* wrong.

your po300 is a random multiple misfire.That is Usually a spark issue..

and the po171 Usual causes for this code:

Leaking PCV Valve Hose
Contaminated MAF Sensor
Leaking Intake Manifold Gaskets
Bad O2 Sesor

This code is set becasue the PCM inputs indicate that the bank 2 cylinders are running too lean to be corrected. This is based on
readings from the MAF, TPS, and Bank 2 O2 Sensor. I'd check the PCV valve hose first. Then I'd consider cleaning the MAF.

Random misfire can also come from a failing fuel pump, and he has not checked fuel pressure yet.

ah ha well that would definatley be something worth checking

Got it back from the mechanic, and he said its the transmission. Doesn't explain the codes. It sounded expensive to fix.

get a second opinion

I think you hit on the problem many posts ago. If you can smell gas in the vac hose that goes to the FPR, the FPR has failed. Gas does not "leak out", it gets sucked into that vac hose into the intake system.

Check it again. If you still smell gas in the vac hose that goes to the FPR, replace the FPR. It can cause the symptoms you are experiencing.

turns out that a temp sensor was telling the computer that it was -38 degrees occasionally. replaced that, all ok!