I've had a bad missing problem with my car lately. Around 35-55 mph, it would miss when cruising. It wouldn't miss at all when idling (warm) or when accelerating, just cruising. It didn't matter if it was in park or under a load (brake torquing). Anyway, went through plugs, wires, cap and rotor, sensors (O2, TPS), etc. Never could find anything.

Today I decided to disconnect the EGR valve, plug the vacuum line and now it runs like a champ? I didn't think these were symptoms. Fluke or do you think this is really the problem?


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Oh, no codes in the ECM.


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No, Those do actually sound like symptoms of a bad egr valve. It may have been recirculating too much exhaust into the intake at cruising speeds. The same thing happened to an old mazda mx-6 i used to own. No codes in that case either.





99 Base model coupe with custom scratches, dings and dents.
Complete bodywork & paint in progress...I really need to update my sig.

Interesting!

Any consequences with having the EGR disconnected for a bit? The local shop has to order one and it won't be in till sunday. I would like to drive it before then.


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I've been running mine since September with the EGR port plugged. I keep saying I'm going to get a new one (old diaphram leaked), but just never seem to think about it...

Well for starters the egr will not ever set a code on first gens.Second unplugging the vac line or lines will not hurt the car unless u get a few less miles to the gallon thats it.I replaced mine several yrs back and ran it for a awhile unconnected and not one issue,minus a little fuel mpg.Normally the egr loses vacumm or sticks and can cause the car to choke once warm, idle crappy or cut off maybe when they start to fail for the above reasons.Nothing to worry about.