Well, I am having some problems with knock. I have had the all to familiar piston slap since I bought the car, but about 6 months ago, it started knocking a little. I switched to Premium gas and it went away for about 2 months.

In August, I got a CEL light which turned out to be cylinder 3 mis-fire. I checked compression and spark and both were good on all 4 cylinders, so I switched the #1 and #3 plug to see if it was a spark issue. Next day I got a cylinder 1 misfire code.

I put new NGK platinum plugs in and cleared the code. All was good for two days or so. Got the same code again, this time cylinder 3 again. Checked the impedance on the wires and they were fine, but I tried replacing the wires anyway with an 8mm NGK set. Code dissappeared for two more days.

Got cylinder 3 misfire again, so I swapped the fuel injectors from 1 and 3. That was two months ago and the CEL has not come on again, BUT the knock has steadily gotten worse, and at idle with the brake depressed, the RPMs drop to about 350RPM.

I had the injectors cleaned which did nothing, had an engine vac which was a waste of money, tried lots of injector cleaner in the tank and nothing.

To make matters worse, my mileage has got straight to hell. I used to get between 625-725 Km per tank. I now get 375-450 Km.

Any ideas?

Id be in the market for a new motor.