bojan

i just got a 10v 200tq a few months ago and everything worked fine. i guess i was in denial since my car's performance has been getting worse. The gas mileage dropped from 23 to 17 mpg, it takes 3-5 sec of cranking to start, the oil temp stays cold etc. I pulled the spark plug and it was totally black. Also, boost only shows 1.2 max. Now, i have some ideas about these symptoms, but i want to know what you guys think. The car still runs fine, but those little problems annoy me.

Quattrotrac

Do you know off hand when the last tune-up was??
Scortched plugs, fuel economy drop, longer starts......off the top of my head, I'd say start with the spark plug wires.

cuatrokoop

Yeah, i'd just give it a nice tune-up...

Plugs, wires, cap, rotor, fuel filter, air filter, oil filter, and check the O2 (replace if needed, OE or generic, both work).

SteveAngry

Do a general tuneup as suggested by the others. New plugs(BOSCH SUPER TRI-ELECTRODES)wires, cap, rotor and air and fuel filter. Also have your timing and mixture checked!

Now for the low boost/temp problem. Could be a bad Multi function temp sensor. This controls a couple of different features. One being the temp gauge on your instrument cluster. It can also send a false signal to the ECU causing low boost. Replacements can be bought at www.performancemotorcars.com

The part number was posted about 3 weeks ago on this forum. Search back for "MFTS" or "mutlifunction temp sensor"...

Also check all your random boost and vacum hoses. The boost hose from the intercooler to the throttle body likes to split underneath and you'll lose boost. You must remove the hose and inspect it!

Your oxygen sensor may need to be replaced sometime soon also...

Steve
Michigan

srigs

Check what everyone else said and.

Plugged Air Filter can lead to poor MPG.
Plugged Fuel Filter can lead to poor starting.
O2 is a must.
Last is fuel pump.

bojan

thanks for all the input guys.
i braved the freezing temeratures yesterday and changed the fuel and air filters. they were in decent shape but needed replacing. Plugs and wires have been replaced 3 months ago, so I'm suspecting a bad O2 sensor for my poor gas mileage.