07 Nitro Lean/Rich/Evap/o2/EGR

[STL_G8GT]

Guy in town here has a 2007 Nitro and asked me to give it a look. Id like some input on where to start, ie what to replace first.

p0171 Bank 1 Lean
p0172 Bank 1 Rich
p0456 Evap very small leak (his dash reads gas cap, but he has replaced the cap)
p1404 EGR closed performance
p0131 B1S1 o2 low voltage

I cleared the codes and will see what comes back over the next few days. Who knows how long the CEL has been on.

Usually I'd throw a new o2 at it and see what shakes out, but because of the long list, I'd like some input.

I'm thinking an evap leak somewhere on the top of the motor causing all of these problems - but not sure how the EGR code would tie in.

Any thoughts?

Vehicle gives no other indications of problems.

[STL_G8GT]

Cleared codes last night and had him drive it home and around. Came back by this morning with just the following codes

p1404 - EGR
p0300 - Mult ran mis
p1404 - EGR


His Evap hadn't completed a cycle yet, so no surprise that no codes are from there.

p1404 is the same as yesterday, so we're going to throw and egr at it and see what shakes out.

[STL_G8GT]

Cleared codes last night and had him drive it home and around. Came back by this morning with just the following codes

p1404 - EGR
p0300 - Mult ran mis
p1404 - EGR


His Evap hadn't completed a cycle yet, so no surprise that no codes are from there.

p1404 is the same as yesterday, so we're going to throw and egr at it and see what shakes out.

Went to remove the EGR and found that the tube wasn't tightened to the EGR from the intake. The gasket was missing, of course. Removed the old EGR, installed the gasket with the new one and tightened her down. Started the car and no more egr codes and no mult rand misfire.

Checked out fuel trims and saw that the LT fuel trims for B1 were in the THIRTY PERCENT RANGE... Check o2s and B1S1 wasn't reporting any voltage at all. Ran over to Napa and paid way too much for an o2 sensor and replaced it. The old one was jet black with soot all over it. Started her back up, immediately ST fuel trims on that bank were in the -20 range as it attempted to correct for the LT swing. Fuel trims eventually calmed down.

Still have the GASCAP message on the dashboard, but it will take three drive cycles or so to run another evap. I found that small leak codes are triggered by a non-invasive test that's ran on the ESIM (vent system) when the ignition is off. Something about a check valve position sensor on the ESIM mounted to the charcoal canister. If the gascap code doesn't clear in a few days, that's my next culprit (ESIM). I don't have a smoke machine but didn't see any visual hose cracks and didn't smell fuel anywhere, either.

Sweet bonus - whoever worked on the car last left a Snap-On stubby socket wrench and wobble extension inside the pass fender well. ($100 worth!)