2004 Ion 2.2 litre Replaced Spark plugs, Ignition Coil Module, Fuel Injectors....runs great if rpms are above 1,000...when at idle there is a little mis here and there. Will throw a P0301 code every couple of days. I have put fuel additive to remove any water. Tried high octane gas and Lucas Fuel Treatment. Still same results. Any suggestions?

 

Miss at idle. Check for intake leak and do running compression test. Could be weak valve spring.

 

It's a lot less expensive to ask questions of folks than to throw parts at the vehicle...,

 

It's been a minute. To check an intake leak, would you spray (WD40 or Carb and Choke Cleaner) around the parameter to see if the idle changes?
A (running compression test) I do have a compression tester! Start on 3 cylinders, or just check each one with all plugs out, so it cranks over easily and quickly?
Thanks in advance! 💯

 

The vehicle is extremely clean and only has 157,000 miles on it. Catalytic converter is fine. Plenty of exhaust coming out the back. Never a P0420 code.

 

Spray carb cleaner around the seam of the intake. No change.
Running compression test.