Help! Horrible idle and acceleration etc [Archive] - Forum


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06-12-2011, 09:51 PM
About 2 weeks ago my 2001 3.4 SE1 started acting up when I was in San Antonio (2 hours from where I live). Ran the codes and it said egr insufficient flow and random misfire. So I went and had new sparks put in at CARx which didnt help. Went to autozone and bought a new egr valve and self installed for $75. Still didn't help. Unplugged said egr and nothing happened, also unplugged mass airflow and that did nothing. So here's what it's doing
It has 139000 miles on it btw
Really rough idle, especially with the AC on, rpms jump back and forth
Rough and slow acceleration, not as bad with the AC off
Sputtering from the exhaust, also exhaust is heating the inside of the trunk, melted a trash bag and scorched some papers that were in the tire well (bad wasn't in the well)
Usually I get a quarter tank or slightly more to S.A., but it ate 3/4 of a tank on the way home. Tries to shift between 4 and 5k rpms, once I hit around 30mph it gets a little better but SE light flashes for a moment, after that it's still on
Need a possible solution soon, otherwise I'm going to sell parts off if it too exspensive. Body is in great shape, interior too.

06-12-2011, 11:22 PM
That is a tough one man, could be a number of things. I hope Aaron has some insight into your issue.

I would say with those miles and a flow issue on the screen that was not the O2 or EGR, would have to be a clogged cat issue. The clogged converter will cause a bog, piss poor gas. But that does not explain the AC issue. The heat could easily be from a bad cat too, along with the flow code.

The bad MPG with the gas getting eaten up could be your coil packs too. It would cause spark issues and rough idle.

06-13-2011, 08:37 AM
I think the AC issue may just be the fact it's putting more work on the motor since of the blockage. Like I said it was fine until then, and it's been throwing the egr code for 2 years

06-13-2011, 03:07 PM
Could be a clogged cat, or bad coils or a bad MAF sensor maybe. There are some other maintenance things that could contribute to something like that, but would not cause those problems by themselves I wouldn't think. The exhaust getting that hot is a really weird one, and definitely points a possible cat problem. Especially if it's been getting an EGR code for 2 years.

Hate to say this, but this could possibly be your fault... or at least it was telling you something was wrong a long time ago and you didn't listen. When you get a code you should try and fix the problem. Just don't keep driving it for two years because even if it seems fine there may be some underlying problem that will cause an even bigger problem later. It does more damage to keep driving it when something isn't right.

Anyway, replacing the plugs was probably still a good idea as it rules those out of the equation. If there's anything else on the regular 100k maintenance that you haven't done yet (ie replace fuel filter, O2 sensors, air filter if needed) then I would go ahead an replace those too. The cat and rest of the exhaust is usually only warrantied for 5 years or 100k miles also, so it may be that the cat has just gone bad.

06-13-2011, 03:21 PM
^Glad I had a second opinion. Aaron and I agree it *should* be the Cat converter, and coil packs. Could be anything but that is your best bet. The O2 sensor could be an issue now with the heat put off with the cat making a mess of that sensor.

06-13-2011, 04:15 PM
Actually 2 year ago when it first came on I did take it in because it was under extended warranty. They "fixed" whatever was wrong with the egr, replaced coils, and fixed the cruise control and said it had broken from the throttle. Also when I first bought it I had to have a lower intake leak fixed for leaking coolant constantly, and a few months ago the fuel pump died on the road.

06-13-2011, 05:33 PM
Good to have that info. The more you can tell us, the better we can tell if it may be related to your problem or not. ;)

06-14-2011, 11:21 PM
Sorry about the brief posts, mostly done while taking a smoke break on my iPod. Haven't messed with it since Sunday. Which Saturday I bought an '07' focus 4 door hatchback, all black and black interior fully loaded with 39,000 miles on it for $10k, plus $3k for and extended 36k warranty and gap coverage. Figured since the GA was paid for I'd keep it as a second for my wife to drive once I figure out what's wrong with it. The focus is nice especially for gas, I know my 3.4 wasn't the most conservative when it came to consumption. Still miss driving it though. From my responses here and on the GA owners club it seems everyone is saying about the same thing so I may have that stuff checked first. If it doesn't work out I'm sure people would be interested in some parts :/

sugar ray
06-16-2011, 08:15 PM
I had a "similar" issue with my 02 about 3 years back. For WAS my cat. plugged with extremely low miles on the car at the time. A solid give away is the bad gas mileage. be sure I would have it checked out so your NOT replacing something unnecessarily. I am usually pretty good with figuring out what's wrong but this one had me stumped.

When mine croaked I took it to the stealership to have it diagnosed properly. They quoted me $720 installed for the direct replacement GM converter. I told them to JUST diagnose then call me. When they called with the quote I laughed very loud in to the phone and said I will be by to pick up my car don't bother putting in the cat. They charged me $46 for the diagnose.I would recommend an aftermarket converter. I drove to a local muffler shop and had an aftermarket converter installed for $175 (included labor) compared to GM's $720 direct replacement quote.

Or if your real crafty and have no air care in your area......cut the converter out and go straight pipe :hay: