2003 Monte Carlo SS (N/A): I just turned 160,000 with the original engine and trans. I bought the car with 105,000. The day I bought the car, it hit the governor no problem (126MPH, closed track ). As of today, it seems a bit sluggish, and doesn't want to even look at 126 on the same "track". Are there some tips for getting some lost horses back? Here's the maintenance since I bought the car:

• Oil change every 3,500-4,000 (conventional 5W-30, Wix Performance filter)
• Spark plugs and wires at 135,000
• Air filter at 145,000
• Injector cleaner every other oil change
• Ethanol-free 91 round the clock
• New Magnaflow catalytic converter at 140,000 (no MIL)

There might be some more I'm missing, but any input would be great!

 

There's a lot of things that play into a car with age, mileage and performance. Take a look at the thread below, it may give you some food for thought on additional maintenance items:
https://montecarloforum.com/forum/fw...0-miles-46078/

 

hey I am having issue with bad mpg,booged down sound, no acceleration, passing gear wont go,cleaned k&n cai,added seafoam to gas? going to clean MAF sensor today any other clues? Bad cat?? thanks

 

Ok cleaned MAF sensor,no fix! engine runs and revs smooth,just bogs down in second,third,step on it and passing gear,engine revs up but does not jump into lower gear? otherwise shifts ok, a little iffy,gas mileage is poor!! Uggghh!!

 

I know you replaced the cat, but that does sound like a typical cat problem.

 

Black sheep, Claydoh here! I have not replaced my cat,90k on car,I think the other poster, dc1 had his cat changed, are my sympyoms typical of a bad/clogged cat? it doesn't seem to be red hot glowing? I also read somewhere that a bad MAP sensor could cause my problems?? thank you!!

 

a clogged fuel filter will cause it to bog down too

 

ok it was my cat! had a new one installed and the Monte runs like a scolded dog!! yea!! another question, where is the pcv valve located on a 03 monte 3.8??

 

Good to hear!

The PCV is located on the passenger side of the UIM.

 

can you be a little more specific on the location of the pcv valve for me? not to sound stupid but?? : )