SilentCool

Didn't think it was necessary to start a new thread, this one has a good bit of info. I believe my misfire is caused by my egr valve or somewhere in the system. I have been trying to rectify an egr problem for a couple months now - getting a P0401 egr flow insufficient code. I decided to tackle this issue myself by running a few tests referring to the service manual since none of my egr system vaccum lines were loose or disconnected. Everything checked out fine, I believe there was one more test for me to carry out but didn't get the opportunity to complete that test. Somehow, fiddling with all vaccum lines did the trick or at least I thought so. I ran the car for about 250 miles with no issue. Yesterday the car was bogging, almost dying below 1000 rpms. I pulled to a side street parked up and looked under the hood. Basically, I just did the general check up to see if anything was loose or out of place. Couldn't find the issue. After a few revs the issue disappeared and idle was back to normal, I put some injector cleaner in the gas tank, assuming it was a gas issue. The only thing I did right before this issue appeared was fill up at the pump. Last night into the early morning omw back from work after getting off the highway the issue returned, this time I got a CEL with a P0401, P0301 code which leads me to believe that my egr valve is complete toast and it is causing a misfire on cylinder 1. If anyone can shed some light, all help will be greatly appreciated.

Automatic 51

iTrader: (2)

When the egr valve goes it does let unmetered air into the intake so its possible it could be running lean enough to cause that issue. Replace the egr and if you're still getting a misfire then spark plugs and/or coil packs could be the issue.

SilentCool

Thank you for the response. I will definitely try that. Hopefully I can get by in the meantime. The mere fact that there is a P0401 code it must be something to do with the egr. So I'm guessing that should work. Will update here as soon as I get this sorted. The cheapest I see the Egr is from rockauto so it should take a few days to a week before it gets here.

rdcollns

My wife's Lancer seems to be having similar trouble, but nothing shows on the OBD2, and having the A/C on seems to trigger it.

I'll start with the spark plugs, but I see many people say NKG. I like the Bosch plugs with no need to gap. Is there any reason not to use those?