Question about 1999 Jeep Wrangler

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1999 TJ Wrangler/Sah runs rough after warm

Jeep runs poorly after it has warmed up to normal op temp. Chugs,surges and pops in exhaust pipe. Runs better when in cooler weather but still runs rough. I have changed: Fuel Pump,Cat converter,Coolant temp sensor,crankshaft pos sensor and coil. Nothing has changed. Plugs are newer platinums, wires are new, cap and rotor look good and show no signs of wear or cracks or scaling. Engine smooths out for a short period while driving then sputters and lacks acceleration. Exhaust is not colored or dark. Starts fine shuts off without any knocking or pinging. I have to note that I have a exhaust manifold leak but it is not huge one. I greatly appreciate any help on this from an expert. Thank you!

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We have the same problem on our 2004 dakota. The mechanic says that it could be the exhaust vacuum that needs to be replaced. Also, they also mentioned that sometimes when the catalytic converter is plugged it acts that way also.

Let me know if this helps.

Posted on Jul 14, 2009


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You may need to replace the fuel filter. Have you checked to see if maybe the exhaust system is plugged? To check the exhaust have someone rev the engine while you feel the exhaust coming out of the tail pipe. You should be able to feel quite abit of exhaust from 1 1/2 to 2 feet away when engine is reved to say 3000 rpm. If you can't feel the exhaust then disconnect the exhaust pipe in front of the converter and drive the car. It will be a little bit loud but you will know if the exhaust is plugged or not. If it goes faster than before then it is plugged. Hope this helps.

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