Hi all,
My sons college car limped home and I pulled 3 codes PO401 (EGR valve) PO301 (miss fire cylinder 1) and PO302 (miss fire cylinder 2. some history 138,000 miles car has run without major issues but I did replace both coils 5 months ago along with spark plugs NGK gapped at 31. Car idles a little ruff but jumps when you give it gas any suggestions on where to start. Kind of thinking injectors may be an issue I did add a can of seafoam about a month ago to a full tank of gas I dod that with all my cars 2-3 times a year and have for years. found it concerning to see miss fires on two cylinders each on a different coil pack.

I am a marine mechanic so I can get into just about anything on the cars.

Thanks for any help

 

Well, I'd start with the EGR code. Here's one link to like causes and solutions

https://www.obd-codes.com/p0401

 

Would the fault in the egr cause the miss fires in just 2 cylinders though? I already ordered a new ERG and have the old one and the tub out of the car. It had carbon in it but I have seen far worse the solenoid was dead it would not operate at all. My concern is that cleaning and replacing this is throwing time and money at a much bigger problem. I did check the plugs today look ok gap was good and I tried swapping the coils although cyl 1 and 3 are on one coil and the other coil has 2 and 4 wires all look fine even in the dark looked them all over really well. I am thinking tomorrow to do a compression test any info on what the range is on this engine?