92 7mgte problems

[cre]

Originally Posted by the_snuggler

I don't know anything about cars

This is the killer.... I'm no longer giving long distance courses on auto mechanics; It's a thankless position and seldom goes well.

There is the possibility of a blown head gasket causing those low compression readings you would need to do a dry compression test and a wet test back to back to see if the compression changes at all.

The turbo error code may be a bad airflow meter or an opening or tear in the intake piping.

Codes 24 and 31 will happen if you unplug the airflow meter while the ignition is on, I would disregard that unless it is recurring.

The oxygen sensor is only a trim sensor, for not just check the wiring for shorts and leave it alone.

You can get the turbo rebuilt (if it's a good core) for $600, no need to spend $6,000 on a new one.

A *full* rebuild will usually cost you under $4,000; It depends on the market in your area and the availability of used parts if needed.

I hate to be the kind of person who just says read the f'in manual... but, RTFM:
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/

Take it step by step... start with dry and wet compression tests.