Strange Issue Rough Running/Stalls Out
 

Ok so I am not a car person but my friends have been working on my car all weekend so far. I have a 2002 Mote Carlo SS and I love the car, it's paid off and don't really want to get rid of it. I was driving over to a buddies to get an oil change and all of a sudden my car stalls coming off the interstate. I noticed that gear shifting was strange when I was on the interstate as well.

So I break down and my buddies get there. They check all the lines and try to crank it up and it has to have constant gas on it to make it run. So we get it back to the house and everyone's first reaction was a bad Catalytic Converter. So we took it to the nearest shop and had them change it but the car still ran the same.

So we are back at the house and we put a scanner up and we get codes for the MAF and MAP senors. So we said what the heck and replaced the MAF, MAP, and IAC on the spot. Problems remain.

The car will stay on and idle for about 1-2 mins and then turn off while the Catalytic Converter is still turning red hot. During this time the engine is really loud, sputtering, and producing a fuel smell. Any ideas?

:rolleyes: Welcome to the Monte Carlo Family..

Sorry to read that you are having problems with your Monte :( How many miles on your Monte ?
Did they check your fuel filter ? When was the last time it was changed ? Sometimes getting bad gas can clog your lines & your pump will still supply gas ? Something to check & also your fuel pump could be going bad : (

Please check back to see what our expert tech member's post on your problem...Plus, explore the MCF and use our search engine for same or similar problems ~> Good Luck 4-Sure:thumbsup:

It has 115,000 miles and this is my first issue with it besides an oil leak. Fuel filter came up a couple times but we didn't think we would be getting those codes from that. I will have them check both and report back. Thanks for the quick response :D

Hi Rob, your Welcome & Good Luck, but keep checking back to see what other member's post...It's SunDay & our fourm has many party member's that sleep in on SUnday's :rotfl:
Below is another guess, but it may be worth checking out..~>Idle Air Control Valve


2001 CHEVROLET MONTE CARLO SS 3.8L 231 cubic inch V6 FI (K) OHV ...


www.rockauto.com/.../x,carcode,1368402,parttype,2589,d,2001_ ... - Cached
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Please check notes in each part listing to ensure the Idle Air Control Valve Connector is correct for your 2001 CHEVROLET MONTE CARLO SS with a 3.8L 231 OHV ...

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Shopping results for idle control valve for 2001 chevy monte ...

1998-2005 Chevrolet Monte Carlo Idle Control Valve Delphi 98-05 ...
$38.35 - Partsgeek.com
1998-2005 Chevrolet Monte Carlo Idle Air Control Valve Standard ...
$28.93 - Partsgeek.com
2000-2005 Chevy Monte Carlo Idle Air Control Valve for V6 3.4L ( ...
$38.95 - 1A Auto.com

the funny smell could be your o2 sensor going bad and causing the car to run rich. and too much unburnt fuel getting dumped in the cat would cause it to get red hot when it ignited.

FYI - If you have access to a car scanner, always check for any codes before throwing parts at it. The old cat may or may not been bad and that is a rather expensive part to just replace.

If you have a new cat and it's getting RED hot, I'd be curious if you have a plug somewhere in the exhaust stream not letting the exhaust flow (could be as stupid as a critter crawled in and died somewhere). This plugging will cause the car to build up high heat, run for crap and ran for long periods of time, cause further damage.

Now, you mentioned you got codes for the car? What codes is the scanner finding NOW? Just because the code indicates things like the MAF and MAP sensors does not mean they were bad, they just might be the sensor detecting the condition.

How's the idle as far as RPM? Does it appear the idle is running high? If so, you may have a problem with a vacuum line (not to many of them, check them out for signs of cracking). An old trick for finding bad vacuum lines, use a can of starting fluid and spray/mist it around where all vacuum connections are. If you have a problem vacuum line, it will suck in the fluid and you will hear the engine idle change.

At 112,000 miles there are a lot of good maintenance things to do like plugs, wires, air/fuel filters and O2 sensors. Right now, I'd back burner those items until you get to the root of this issue. My gut says something has your idle cranked a little high or your exhaust system is plugged since you state the cat is getting red (this is BAD). It could be a rich fuel condition as noted by Bama_z34.

Get us the current codes in the computer and we can help more based on that data. And I mean the actual code (the number that is provided).

Ok guys thanks for all the replies. We found the problem. There was a hole in the intake manifold. 30 mins at the junkyard and about a hour swapping the part and everything is good.