service engine soon light came on...

[AaronLG]

what would cause this? how do I diagnose the issue? can they check the code or is it something different since it's not the check engine light? I think it came on about the time I did my exhaust but it went a way for a while.

 

[Canadian Expy]

yeah you should be able to scan for codes, what did you do to the exhaust?? Did it cause O2 sensor to throw a code?

 

[Explor2Exped]

Did you check for codes?

 

[AaronLG]

Haven't checked for codes, that's another issue, fuse for port keeps popping. had the rear cat removed, didn't think there is a O2 on it. maybe that's the issue.

 

[Canadian Expy]

If you removed the rear cat that can throw codes. did you put a new front cat on? you can get away with a single cat if the new front cat can handle all the extra pollution. Also there is a rear O2 that if put in the wrong place, distance from the cat it can also throw codes. How do you like the rear cat delete?? I want to do that badly but not sure what new cat to get? so I don't throw codes. Magnaflow makes some but unsure which model to get???

 

[AaronLG]

Gave it more sound for sure. Haven't noticed much of anything else. Would a programer be able to clear it?

 

[KWT2000]

make sure the rear 02 sensors are plugged in... i am still running the stock front cats with the rears gone and no problems...

but also your front cats could be bad...

with that fuse popping it could be a different porblem all together

 

[Canadian Expy]

Gave it more sound for sure. Haven't noticed much of anything else. Would a programer be able to clear it?

I know my Edge reads and clears codes

 

[walnuts4x4]

+1 for edge clearing codes.... and no problems for rear cat delete....

 

[Tigster]

any auto parts store will pull the codes for free so you can see what it is first.

 

[Canadian Expy]

+1 for edge clearing codes.... and no problems for rear cat delete....

You did a rear Cat delete, so did it make a difference at all? And did you replace the front one with somthing different?

 

[AaronLG]

You did a rear Cat delete, so did it make a difference at all? And did you replace the front one with somthing different?

nothing noticeable. just sound.

code is p0401. EGR system fault.

Truck drives fine though. guy at autozone said it should try to die if that code is showing.

 

[AaronLG]

Any clue how to fix p0401?

 

[KWT2000]

check the DPFE and the lines running to it.. make sure the EGR is working and hasn't gone bad...


my money would be on a bad DPFE

 

[Thermo]

Aaron, I second the DPFE. It is the little box just in front of the EGR. it is a cheap part and easy to replace. Mine failed and it was due to the ports on the DPFE getting corroded by the exhaust and they got plugged up, leading to the computer not seeing the EGR valve working.

 

[walnuts4x4]

I'd agree with DPFE.... not too expensive and very easy to fix.... less than 5 min... and that includes a beverage in that time limit...

 

[walnuts4x4]

You did a rear Cat delete, so did it make a difference at all? And did you replace the front one with somthing different?

only thing greatly noticeable was it sounded a lot better.... also had a true dual setup done when I had that done...

 

[AaronLG]

Thx guys. I'll try to find it.

 

[AaronLG]

Can someone snap a picture of what I'm looking for. I'm lost.

 

[walnuts4x4]

http://www.f150online.com/forums/v8-engines/233290-dpfe-sensor.html