lcseydel

I was able to run a test on my fuel pressure, and it acted as expected, also did the hot shut down and saw an increase in pressure as expected. The search bar in advanced measurements module is a life saver. The above video made this test very easy.

So I am back to the O2 sensor, pre-cat, drivers side. It had a wonky connector, so I zip tied it, it helped slow down the readings to intermittent. I have ordered a replacement, and the right housing to fix the connector. I will repost after next week when I've completed the work.

NotoriousGLU

I am sure happy it is not a HPFP. Well must be that darn connector then.

lcseydel

So I replaced the Upstream o2 sensor, rebuilt the connector, and all cleared up for a bit, then started getting "too lean" codes again, but no misfires. Frustrating, but am considering replacing the downstream sensor, since that is the one issuing the code. Probably will drive it for a while to see if more codes pop up.

lcseydel

After 100 miles, no codes recorded as permanent. Intermittent 2089 is gone!!!! Bad connector or bad sensor, I'll let you know after my 1500 mile trip.

NotoriousGLU

Sounds like a great progress !!!

lcseydel

Well the sensor codes are gone after replacing the upstream sensor and fixing the connector, and the CEL was off for most of the trip. Now I am seeing P0300 and P0306 codes. I changed the coil packs between 8 and 6 to verify that it was not the coil pack on 6. Code P0300 and P0306 stayed as previously detected. I noted that the spark plugs, Autolite XP3924 were gapped at .032 which seems tight (spec'd at .044) and they were that way on all four left bank plugs. It is possible that that plug is bad but all of the plugs had the same burn pattern, looking a bit lean, but not bad. Next up is an injector, I suppose, then perhaps a compression test. Don't know what else to look at?

Tired of chasing this CEL,

NotoriousGLU

So I used to buy Autolite and my moded A8L was misfiring like it's nobody's business. Came to find out sparkplugs from Autolite are just terrible. They were bending all over the place. Now I have NGK and honestly they are just perfect. Try to buy a set of NGK and install them. If I remember correctly for my car gap is 0.025 because of the mods on it. But on 4.2L gap shouldn't be grater than 0.032.

lcseydel

Yes, I replaced all of the plugs, and my problems cleared. No more Autolite. I also had Autolite plugs in a skid steer, and one of them went bad as well. Done with that brand.

lcseydel

Also replaced one injector after moving the injector between two cylinders to find that issue. All running clean now.