PLEASE HELP!!!!!!!!

[Keith607]

Ok so i have a 2002 buick regal ls it has 128k miles on it. So when im driving especially getting on the highway it starts to shudder and i cant figure it out. I have changed the tps, fuel filter, fuel pump, air filter. I changed all that and sparks plugs and wires and coil packs and maf sensor and both 02 sensors over the last year and this just started happening. No check engine light on sometimes while shuddering the check engine light blinks the odb reader says multiple misfires. I noticed today one of my spark plugs was shaking a lil bit but no other ones. Anyone have this problem or a solution?

 

[Regal LTD Coupe]

I had a '99 Grand Prix GT with the Series II 3.8. It often gave a similar problem but I never bothered to fix it before someone hit the car and it was written off; it just kept running and running. I noticed if I changed the PCV valve it would be good again for a while but would soon be doing it again. If I still had the car I'd have probably replaced the catalytic converter and muffler by now; a Magnaflow setup is like $160 and maybe another $140 to be welded in. It did in fact have a check engine light on as well but I never had it checked. Was probably closer to 175,000 miles when I last had it.

 

[Regal LTD Coupe]

I have also heard that if the crankcase is filled with too much oil on this engine it may do something like that; may likely clog the PCV valve as well.

 

[Keith607]

I have also heard that if the crankcase is filled with too much oil on this engine it may do something like that; may likely clog the PCV valve as well.

So checked pvc valve not it its good spark plig wire is a little loose and hesitates to start too

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[Regal LTD Coupe]

Is there a check engine light? I think places like O'Reiley's or Autozone can check it for you. I'm assuming it's the cat but unfortunately changing the exhaust on a whim isn't cheap. I already had the parts for a year or two on my Cadillac for a similar but worse problem (couldn't even drive it anymore; motor sometimes wouldn't start and would die going up a slight hill) I took a stab in the dark and changing the catalytic converter and muffler to Magnaflow totally fixed the issue I was having.

 

[Keith607]

Is there a check engine light? I think places like O'Reiley's or Autozone can check it for you. I'm assuming it's the cat but unfortunately changing the exhaust on a whim isn't cheap. I already had the parts for a year or two on my Cadillac for a similar but worse problem (couldn't even drive it anymore; motor sometimes wouldn't start and would die going up a slight hill) I took a stab in the dark and changing the catalytic converter and muffler to Magnaflow totally fixed the issue I was having.

I changed the plugs and wires seem to be good now we shall see ill update if not.

 

[Regal LTD Coupe]

Good fix.

 

[VegasDude]

Make sure you ALWAYS use Genuine AC Delco Plug wires, or Very high end wires... NOT the typical junk from auto parts stores.. They won't last long. My '96 Regal had that issue shortly after I got it.. Previous owner had replaced the wires a year prior... They were from an auto parts store, and they were shot..
EVERY mechanic, and GM gearhead I know has said you can't stress that point enough...

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