Yes I'm breaking the unwritten forums rules and going outside the Chrysler brand for this question reason being, I just can't seem to get much help on the proper forums, and after all, we are all car and truck guy's well, mostly truck here but you get the idea...

Wife's '02 Buick Century 3.1L V6 runs like a slug. The fuel filter was clogged so I replaced the fuel filter also replaced the air filter, MAF (cracked), and TPS (tested bad).

Car idle's fine and has plenty of power in first, enough to spin tire's (front wheel drive) soon as it hit's 2nd it's done, if you push down on the accelerator it bogs and doesn't do much of anything until you let off the gas and it will shift and gradually gain speed but I really can't get past 55mph. It threw multiple random misfire and EGR code's, the jerkyness went away with the new fuel filter as did the misfire code's, took the EGR off, cleaned it (it wasn't the least bit dirty), EGR code went away.

Today the jerkyness seems to be back a little and the service engine soon light is on but I don't have the Actron here so I can't tell what it is, and I don't wanna push it to the parts house..

I tested fuel pressure today ($150 to rent a damn tester BTW) it's getting 52PSI solid, book calls for 48-55PSI, so I don't think it's the fuel pump, and I was actually hoping it was....

I thought about a possible exhaust restriction but it seems to flow fine.

The car got new AutoLite Platinum plugs and new wire's about 2 years ago, I pulled a plug and they look great, nothing wrong with them.

Does anyone have a general suggestion to try? I know it's not a Magnum engine but it's gotta be something sorta simple...

The car doesn't have a distributor, it is coil pack's if that helps any...

Thanks for the help.

Edit:

I put this is the GD section since it's not Dodge related.

 

Remove the front O2(s?), and see if it's any better.

Aside from that, I would start thinking possibly a trans problem.... can you feel it shift thru the gears, and TCC engage? 4spd auto??

 

I had thought about taking out the 02 Sensor too, I'll do that tomorrow, it shall be fun to do as it's up by the firewall just below the spark plugs.

I can feel it shift through gears but ONLY when I left off the gas, if I floor it, it will not shift until I let off a little.

3spd auto with OD. It does the same thing when I put the gear selector on "D" instead of "OD"

I thought about the transmission too, even wondered if maybe it was in "limp" mode. Disconnected the positive battery cable today and left it off for about an hour while we were gone, no change.

I can only hit about 55 so I don't think I get to the OD gear yet, but I'm not sure when it's supposed to kick in.

The car has over 120K on it and it's more then likely on the original fluid and filter, it needs a change but I don't wanna do it till I get it running right, unless the transmission is the culprit.

The car has been a little sluggish for a while but never this bad, I mean we took 2 trips to Atlanta in the car just about a month ago and it was 100% better then it is now, so whatever it is it's getting worse.

 

What's your rpm at at 55? (bet it doesn't have a tach..... )

 

I'd bet you'd be right, no tach....

It sorta seems hopeless but there is a shop in town that is pretty good and supposedly only charges $35 for diagnostic's. If pulling the O2 sensor doesn't help I think I'll have to take it to them, hopefully they're open for a little bit on Saturday....

 

Man is it going to be a pain to get the O2 out, it's buried just deep enough to were you really can't get to it from the top. this blows!

 

a guy at work had a pontiac with the 3.4 that did alot of the same things his transmission had something wrong and it cause the car to run open loop all the time and one or two of his injectors were stuck open....i cant remember for sure what was wrong let me try to call him and see

 

Update:

I made a discovery just now, I got back to thinking about the EGR code and how it wasn't dirty at all when I cleaned it, after a cold start 5 minute drive the EGR valve get's extremely hot, much hotter then the exhaust and the engine itself, being it's electronically controlled I unplugged it and took it for a drive, it runs a lot better, I got it up to 70, there still some slight hesitation but it's no where near as bad.

I'm wondering if the EGR isn't bad or if the ports on the intake are clogged up, I don't think I checked them...

 

I don't think I have ever had any issues with EGR before...so I don't really even know what the heck it does (or doesn't do). I would assume it could cause run or idle problems. Got a Haynes for that car?

 

Unfortunately no Haynes Manual. I got a new EGR valve, it still runs better but not 100%. The motor seems to get very hot after just a few minutes of driving even from a cold start. Also we've noticed a bit of a sucking noise that seems to be coming from the driver side, but we can't find any vacuum hose's broke or disconnected. But we made another discovery today while looking at the motor, I found a water leak on the driver side of the motor (technically the side since it's in there sideways) at the intake manifold gasket, I'm guessing it's got a blown head gasket, not sure how else water would be seeping from the intake gasket's.

But I'm not doing anything else with it until I resolve that issue, and first thing will be to try and trade it in, we've got a few really good car lots in town and one of them has a nice Cheby Tahoe.

If we can't get it traded I'll tear into it and see what's messed up.