Will a bad tank of gas cause a CEL? I got one and everything checks out, injectors are recently cleaned new plugs after a fresh valve adjustment, compression is 215 210ish across the board valve leakage is a little high on cylinder 2 at 9%. I put in gas and the car has been running like shittake mushrooms. I've been going nuts trying to figure this out, just occured to me the car feels better after a new tank of gas. So I guess I'm asking if bad fuel will cause a CEL, or should I keep looking?

 

Short answer is it may. What code(s) is she throwing?

Utah

 

It was the misfire codes p03xx, all of them. Turns out it was a stretched timing chain. I replaced all injectors with new ones, new coils, new plugs, new fuel pump, nothing fixed the misfire. So I checked the valve lash for ships and giggles, turns out the marks on the cams wouldn't line up, and if they did the crank was way out of time. So waiting on a new chain and see if that does the trick. I guess at 190k miles it's to be expected.

Now I can fix the leak on my oil pan.

 

Can you measure both chains? Just curious how stretched your OE chain may be.

-- Chuck