Runs Rough Unless Warmed Up

[sleepn_sn95]

A few weeks ago I got a new exhaust installed (Dr. Gas O/R X, Magnapacks) and ever since then it has not run right. Before the new exhaust I had an o/r h with flowmasters and I would just start it up and drive it. Now I have to let it run for about 10 minutes before I drive it or it runs really rough and cuts out. When I accelerate from a stop, it cuts out until I give it more gas then its fine. Also when I first start it, it idles fine for a second then it jumps up to ~1500 and the CEL starts to flash, then it drops back down and idles fine at 800-900. Brand new motorcraft plugs and wires were put in thinking that would solve the problem, but it still isnt running right. What do you guys think the problem could be? The car is also an automatic if that would matter.

 

[blkmcnasty]

Off the top of my head im thinkin bad 02's. But also what did you do with the smog tube that runs to the mid pipe?

 

[MustangMoser]

thats weird, are the mufflers clogged? drop the x pipe from the headers and see how it runs straight headers.

 

[kennebellgt]

^ What moser said, also Same thing happened to me, what i did was reset my computer than it ran good again, try it, its worth a try, disconnect both your battery cables and touch them together, see if your problem goes away.

 

[Venomous96Cobra]

wow! that's funny my 95 used to stumble on acceleration upon take off if I didnt warm it up at least a few minute's, it would only do it once and it was annoying.... I solved the problem by you guessed it!!!!

warming the car up for a few minutes.... nothing wrong with letting the car get up to temp.... :wink:


but enuff of me being a wise a*s!

1. check the temp sensor
2. clean the egr
3. check and clean your maf with maf cleaner

and here's the most obvious and where you should have started!!! Fuel filter :wink:

And someone correct me if im wrong but a flashing cel usually means that you are having an engine misfire!!!! so check your ignition coil and distributor as well