turbo? Knock sensor? running lean?

[IHateHacks]

I'm telling you, you are running too much boost.

You can rule out 80% of what this "shop" told you.

You can check the resistance of the fuel injectors, 1.8-3.4 ohms for turbo models, but I already have the feeling you need bigger ones, and a bigger fuel pump running that much boost.

You should have replaced the fuel filter before you even started driving this vehicle so if you haven't yet, do it.

Accordian hose? Take it off and check for cracks. Better yet, check ALL vacuum hoses for cracks, i.e. ISC hose, PCV hoses, etc.

Like the fuel filter you should have set base ignition timing before you registered this vehicle.

You can test the O2 sensor voltage feedback. Connect a voltmeter to terminals Vf and E1 of the check connector. Voltage should fluctuate 8 times every 10 seconds.

And the cat, well you will have to take it off and look at it to see if its melted.

Or you can turn down the boost and see if thats the problem.

"did that slow down thing"- yeah thats the ecu retarding the timing, like I told you before.