First post here, and pretty mechanically unexperienced.... but I figured someone on here could point me in the right direction.

I've got an expedition that's throwing codes p0402 and p0301... I understand what these codes mean for the most part but not sure which I should attack first. The truck has a pretty rough idle, and seems to be missing around 1500 rpm, also every now and then it dies when i come to a stop... I don't have much extra money to take it to a shop, and it seems like I may be able to tackle this poblem myself.

I'm not sure whether I should be replacing my EGR valve or DPFE sensor... or if there may be some other issue. I also am wondering if the EGR issue may be causing the cylinder 1 misifre? Any help would be greatly appreciated!

Thanks,
Nick

 

How about tackling the easy code first and see if that clears up your rough idle and miss? The code P0301 is for the passenger side cylinder in the very front, you need to replace the COP (coil on plug). You are lucky because it is the easiest one to change. Should only take about 15 minutes once you get in there. You can buy the COPS on ebay from many different sources, I recently purchased them from MapDistributors on ebay and they were at my house in 2 days and cost $9.95/ea with free ship. I had the same P0301 code with the rough idle and miss. Sometimes the engine miss will cause other codes to throw. Once you have changed the COP, pull the battery cable for 10 minutes to clear all the codes and see if the P0402 comes back or not. If you are lucky it will not come back, if it does come back you can attack it.

 

Ok I'll see if I can get a COP today, I'm trying to get my truck drivable by tomorrow morning. Might have to bite the bullet and get one from autozone or something... I think they're about 50 bucks there. But that beats driving around with my engine missing and potentially causing bigger problems.

Thanks for the quick reply Bumparker, I'll report back with how it goes.

 

COP's... Be GRATEFUL that it's not cyl #4!!!!!

 

Ok, swapped out the COP on cylinder 1... but I'm still getting a misfire. Guess I'll do the spark plug, see if that solves it.

 

Usually the misfire is due to the COP. Other possible causes could be the spark plug, fuel injector or a sticky valve. I think you right to tackle the spark plug first, hopefully that will solve the issue.