P 0191 code and rough idle?
 

Twice yesterday, after sitting all night, and after sitting all day at work when I started my truck it idled rough for about 4 or 5 seconds then ran fine. Second time idled rough for four of five seconds and died I restarted and ran fine rest of way home. When I got home checked codes had p0191. So i removed xzt in planning if it happened again to take it to dealer but truck has ran fine today. Any Ideas? Is it the box? Is it fuel system? or is it a fluke? Any input I am very thankful for.

p0191 under a generic code showes it as " fuel rail pressure sensor range/ performance" hope that helps. the web site www.canobd2.com Tech information then DTC library.

Mine did the same thing with a quad race box, took it of and it cleared itself up. My truck also threw the p0191 code with the quad, quad told me something was wrong with my truck, took to the dealer it spent three days over in the shop could'nt find anything wrong.I bought an edge and no codes and the missing at start up is gone.

Two things could have happened.

First one of the connections could have been slightly loose and upon start up the signal the ECM recieved was different than it expected. If this happens the truck uses a pre-set number to run the rail off of. This is the same things that would happen if you just left your truck running and pull the chip off with the truck running.

The other thing is that for some reason or another the fuel pressure, rail pressure or even the cam or crank signal was a little goofy. Once this happens the truck also tries to correct itself and will typically idle goofy.

I would put the module on and keep driving it and see if it happens again. IF it does not happen again then most likely it was a connection issue. If it happens again then either something is wrong with your module or something is happening with the truck.

If the module has a problem it will typically repeat itself over and over.

None of the above should actually hurt the truck, but it will tick you off.


Quad

Thanks for th info guys I'll try my module again this weekend and see what happens. I appreciate all the help from the people here and your prompt reply as well Quad.

I had the same issue with the Edge EZ on my truck. The connector to the fuel rail pressure sensor didn't quiet match the other connector. Ended up having the bend the pins in the connector and use dielectric grease. Solved that issue.
I recommend using dielectric grease on all the electrical connections.

MikeyB