Contour Enthusiasts Group Archives Forums General Troubleshooting Alright Gurus. Need Some Assistance.

Problem 1: About a couple months back I got a CEL, got the codes pulled and got P0171, P0174, and P0430. I know what the codes mean and I figured it could probably be pointing to my O2S. Car has started stuttering under idle and was wondering if foul O2S sensors could be the problem? And also can both the Bank 2 problems (P0174, P0430) be associated with each other? Searched and couldn't find a direct answer.

Problem 2: Noticed one day while driving that my electrical system was malfunctioning. I don't have a Low Charge Light, but did the tests: 12.3V battery charge, 14.3V then drop to 12.3V while running, and 12.3V and dropping under load. Think the alternator might be on its way out. If so, instead of O2S sensor being bad, could a low voltage condition cause the stuttering?

Car: 1998 SE 2.5L V6 112,000 miles.

Any help is appreciated. Sorry for the long post.

Well a PO171 usually means system to lean, could mean 02 censor like you said, mine (its a Zetec) was a vacuum leak. So what I would do is get a new alternator then if that doesen't work, (wait you gettin a battery light too didn't notice in the post, could be a system to lean problem with the stuttering) this is a good question, mine when it had the vacuum leak, it just stuttered with no electrical problems. If your having problems with your lights and such, I'd say your running lean and need the alternator.
And also the post wasen't too long, I've seen worse.

I can't really tell if I am running lean but from what the codes say, I am. I know I need to replace the alternator and that its probably gonna be a b!ioth and a half. I also checked a couple earlier post and think I am gonna go ahead and replace the two upstream HO2S and do the intake cleaning with the B12. Hasn't been cleaned since I got the car. Probably should do that. Praying that it will fix the problem because I am not gonna pay for two new precats, gut my precats since I don't have the tools required, or buy headers. Better off saving to get the T-T-T-Turbo.

Fix what you find then retest.

check the duratec maintenance forum for some helpful how-to's.

straight forward, and with the right tools can be done in 3 hours (even for a newbie to this) 45 minutes out, with luck..

Ray