this question pertains to a 94 lincoln towncar with a 4.6, the car runs perfect once warmed up but the issue is when cold,when i go to start it in the mornings i have to hold my foot on the gas to keep it runnin,id say about 2k rpm's, and during the time im helping it idle you can feel the motor running bad like its running off 5-or 6 cyl,real bad miss, and it also makes popping noises in the intake, once it gets completely warmed up it runs fine, occasionally it will idle funky once warmed but not alot,mainly only when cold, i get the CEL on every once in a while not much and not for long,maybe 10-15mins then it goes out,its OBD1 so i had a shop check it to see if there were codes still stored and not so...,once running i have no issues,car runs great and has lots of power, ive replaced the following in the past few weeks hoping to clear the problem- IAC, MAF , plugs & wires, engine coolant temp sensor , fuel filter, cleaned the TB, PVC, also did sea foam, after all this it still does the same thing when cold, now in the past few days i noticed a noise coming from my exhaust, like a rattling in the pipes up close to the cats or even manifolds?, were do i look next?? cat conv poss plugged,how would i know besides replacing, no rotten egg smell? would the EGR produce this type of sign if it were bad or dirty, i herd you usually just get a CEL from bad egr no running issues usually?? pulling my hair out tryin to figure this out,any help would be greatly appreciated!!

 

your rattling could be something as simple as a heat shield or a loose pipe connection. I had that problem on my truck, just had get under it while it was running and poke around a bit until I found the problem. It was a heat shield. After re-insatlling my engine when I had it rebiult I had the same problem, turned out that I didn't tighten the EGR to Exhaust manifold tube completely. Unlikely that this would be your problem unless you recently replaced it if your car is equipped with one as they tend to corrode pretty good. As far as why it running rough not sure why it would do that, i'm not an ASE cert mech, just a tinkerer.

 

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