Good morning guys! I've belonged to the forum for almost 2 years now but usually just read and don't post.

2003 Monte Carlo SS 3.8 with 95,000 miles

Anyway, I have been researching my issue and have found some posts that are similar to the issue I am having, but nothing that is the same. But I want to make sure I explain it enough, so please excuse the length.

About a week ago, I left work on lunch and as I was just cruising along at 35-40 mph, the car sorta "jerked" once... almost like a backfire or a gasp for air or something. Hard to explain. There are no error codes so I can't just have it scanned yet. But since then, it has done it a few more times and is totally random. It does NOT do this at the time of shift points so I really don't think it has anything to do with that, it is at cruising and doesn't matter if it's 30 mph or 70 mph. It's not a hard enough thing that the car feels like it's going to fall apart, but it's definitely noticable.

First thought is that the Cat is in it's beginning stages of being plugged. But it also seems to be getting pretty hot under the hood, so that also makes me think that there is possibly some backpressure from the Cat... If that is the case, I will prob go with a high-flow Cat and u-bend delete... possibly a full DP even. Anyone have anything for sale? Or is there a forum here on the board for used parts that I can look around in?

Second thought is that it just needs a tune-up, mainly spark plugs and wires, because I already had the fuel filter replaced about 6 months ago. I haven't just pulled one of the plugs out yet to inspect it, but I will do that first... What plugs are recommended?

What about one of the coil packs going bad? What are the symptoms of that, and is there something I can do to test them?

Someone mentioned cleaning the MAF sensor and the intake... but I had this all done along with the injectors and such, also about 6 months ago. Any other sensors I could try to clean?

Thanks for any possible input! I just wanted to try and do some research before I start throwing cash at it and just hope I get it right.

 

I've done more searching yet... I did find a somewhat convincing post that is pointing to the Cat.

Any help please???

 

I agree with the cat probably getting clogged. Any exhaust shop should easily test that for you.

The coil packs going bad would probably caused a misfire, which you clearly aren't experiencing since you don't have a CEL flashing.

We have a classified section, once you get to 10 posts it should unlock for you.

 

Good deal, thanks!

So is it a bad "newb" thing if I just make 10 posts here in my own thread to get that opened up? Haha!

 

It's technically spamming the forum and we could give you an infraction for it :P

Take a look at the daily blog, join in the conversations!!! It's in the off-topic section.

 

Thank you again.

 

Might be your mass airflow sensor. I had to replace mine, same problems as you had. I put it off for awhile and it started doing it a lot more. I thought it was my tranny and had it checked out and it was the sensor. Wasn't throwing any codes either.

Hope you figure it out!

 

When my car shifted rough, my check engine light came on and my transmission sensor went bad. It yours went bad, expect to pay $700-$900 for repair. The repair entails dropping the engine to drill a hole through the valve body to access the trans sensor then installing a kit. I paid a guy $900 to fix mine. Hopefully that is not your problem, but all monte carlos, malibus have the same faulty sensor.

 

I thought about the Mass airflow sensor actually... I may try to clean it and see if it clears up a bit. If it does, then I will replace it. Any tips on cleaning it???

As far as the Trans, I really really doubt that could be the problem. Not saying it isn't, but based on the symptoms I don't think it is. There are no lights on and no error codes thrown.

 

ONLY use MAF spray, nothing else. NEVER touch the wire with anything. Air must must dry it.

You'll also need a torx t-20 SECURITY bit to take it off.