98 Crown Vic Barely Running!! :o( - Page 3 - Ford Forums

fixitnowlt · 07-11-2009, 15:59

I noticed that you only replaced 5 of the COP's. Why not the rest? These things are junk and you may need to do the other three. How did the spark plugs look? Good enough to be cleaned or should they be replaced?

The MAF sensor may be at fault as well. Cleaning it may help but I cannot say that it has worked for me.

Double check for vacuum leaks. This can be done by spraying brake clean around vacuum lines or places where gaskets are present. Notably around the intake. If there is a leak the spray will even out the engine for a second or two and then return to running rough.

evuguys · 07-11-2009, 16:30

I have been replacing the COPs as I get a misfire code, the budget is kind of tight! Anyway, all the spark plugs have been changed about a month ago just for good measure. The old ones were probably still good, but we replaced them anyway. Also, today, I stuck my hand under each exhaust pipe and the drivers side tail pipe exhaust is not as hot temperature wise as the passenger side. Is this relevant to the problem you think? The miss or sputter can be heard in both pipes, though. I checked for leaks again, and none to be found.

fixitnowlt · 07-11-2009, 16:37

You had a P0420, that is for the right(pass) side. A P0430 is for the left(driver) side. It is possible that the cat is clogged up on the left and broke down on the right. They are very easy to get to and take off. You could try removing them and see how it runs then. Be sure to spray down the studs at the manifold before you attempt to remove the nuts. See this article:

How to Loosen a Stuck Bolt | eHow.com

A deep 15mm wobble socket is ideal to get to them but you may be able to use a straight socket.

Fair warning- It will be loud so do it late at night or early in the the morning if you have neighbors you do not like

evuguys · 07-13-2009, 08:24

Just want to say thanks to everyone who replied to my problem. Thank you. To FixitNowLT, thank you as well for all your help with this! I removed the cats per your suggestion, and it ran much better, but still had a slight miss to it. After fixing the exhaust, I went back through the spark plugs one more time to see if they were burning clean or not. What I found was one that was fouled and one that was only partially firing. It looked to me like these two had never been replaced. (I'm gonna kick my friend's b**t for not replacing them all!!)

Oh well, I guess that's why it's better to do the work yourself, huh? I replaced both plugs with new ones and new COPs on each plug and it runs perfectly again!! By the way, I went ahead and finished replacing all of the spark plugs. He had only replaced 2!! Just wanted to tell everyone thanks for your help!!

-EVUGuys

fixitnowlt · 07-14-2009, 20:24

Glad you got it fixed!

beep, beep!