QuestionMy 99 Chrysler sebring had a rough idle. I replaced the dist. cap, rotor, plugs, and wires. The problem actually seems worse now. Since the tune up the check engine light has come on. The codes generated are for misfire cylinder 5 - 305, system lean 171, and multiple misfire 300. I am totally lost, and would greatly appreciate any help you can provide.
AnswerHi Trey,
Because of the indication toward cyl. 5, my inclination would be to replace the fuel injector on that one cylinder as one remedial action. If it were partially plugged or electically compromised that would cause a leaning of the mixture. Because of the multiple cylinder code however, something more general is possible...
Another possibility is that the egr valve is not closing fully, but rather hanging up ajar which will also cause a lean idle condition. So look for that valve near the intake throttle body area and find the valve's stem (in between the valve body, which is mounted to an exhaust return pipe from the front exhaust manifold, and the round vacuum actuator on the top of the valve). The valve is very near the thermostat housing which is also below the place where you add coolant to the cooling system.
The stem is horizintally positioned and has a slot into which you can insert a screwdriver tip and use that to move the stem back and forth.
Spring-action will try to close it, and so you would want to test whether you can move the valve further in the direction that the spring is attempting to, from where is rests normally. If so, I would spray some WD-40 on the stem where it enters the body and work it some more.
There are otherwise a plethora of possibilities for missing, such that I would not get into those until I tried the egr and the injector. Almost anything affecting spark and mixture is possible.
I can give you the list, so do write back and tell me if neither of these suggestions was helpful. Use the "thank and rate" tab to reach me when I am shown as "maxed out" and I will get you note which you can post in the comments section.
Roland
Roland, Thanks for being so prompt. One thing I failed to mention is that the fuel mileage is about half of what it normally would be. Does that make any difference in the approach I should take.
Hi Trey,
Thanks for the kind evaluation and nomination.
You could look into the following mixture-related issues:
Leaks in the exhaust system between the two oxygen sensors
Fuel pump pressure
MAP sensor inaccurate
Coolant temp sensor inaccurate
Intake air temp sensor inaccurate
Those (except for the exhaust leak) would require tests with diagnostic tools.
My suggestions were of the do-it-yourself approach and seem logical as a place to start. I would at least look for the exhaust leaks, if any, and check the egr valve.
Roland
