FWIW your car is not an OBD-II car, but a CAN car. Not sure if your mechanic's reader was a CAN reader or not but using a CAN scanner you might get more info.


It sounds to me like you're going to have to do some research or spend some money at the dealer.

Where did your fuel pressure numbers come from? An actual test? Or where they read from the fuel computer's history or something like that? If the latter those numbers are probably useless, except for the very low one which is much too low. I suppose these low numbers could point to a failing fuel pump.

Are the codes the P code numbers? If so here are the code descriptions:

P0300
http://www.obd-codes.com/p0300

P0301
http://www.obd-codes.com/p0301

The codes may not be unrelated - you may have coil problems. It's worth doing KlausC's bait-and-switch routine to try to isolate a particular coil. Also inspect the housings closely for cracks.

Some new plugs might make this process easier. It'd be nice to find somewhere that was having a plug sale and just buy the cheapest plug available with an eye to putting real plugs in later once the problem is found. Some people have good luck cleaning and re-gaping too.

Despite the one mechanic's attestation that it's not a vacuum leak, I think I would still have it smoke tested for leaks in intake and exhaust.

You can bench test O2 sensors. Do some reading on that.

I expect your car has a MAF of some kind, which can probably be bench tested. There are some writeups on MAF testing on the P1 cars on this forum and others.

Your MAP could be bad - no idea how to diagnose.

Your ETC could be bad too. There should be a way to bench test this as well, but it will require some fairly serious work to pull it out as it's probably either installed into the thermostat housing or actually a part of the thermostat itself...

I hope you figure it out.
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1998 V70 AWD->FWD Turbo 200k+