2003 Buick Century Sputtering

[bezerk19]

I have a 2003 Buick Century with about 109k miles, lately i've been having issues with it when coming to a complete stop and resuming by pressing the gas, once you reach 20mph the engine starts to sputter after a few seconds its okay then reaching 40mph the same problem occurs.

I've replaced the spark plugs, the wires, the fuel filter, the pcv valve i've taken it to get a fuel injection cleaning and transmission flush, not sure what else it can be???

The service engine light has been on for a while, Autozone said it was a misfire, but after the fuel injection cleaning it went away, but after some driving it came back on.

What i have noticed is that when i reach 20 mph once it has problem i let go of the gas, then step on the gas again so that it won't struggle sputtering i feel the engine jerk (not a transmission jerk) but that feeling as if the car might day (more sputtering)

Any one have any ideas or suggestions???

Thanks,

[richtazz]

Can you post the actual codes AZ pulled for you or have it re-scanned and then post? There are multiple issues that can cause your symptoms, so having the codes would help us greatly and eliminate a lot of guessing.

[bezerk19]

Originally Posted by richtazz

Can you post the actual codes AZ pulled for you or have it re-scanned and then post? There are multiple issues that can cause your symptoms, so having the codes would help us greatly and eliminate a lot of guessing.

Well I had a chance to take it to Autozone, they said its code P404, the problem causing the Service Engine light was due to the EGR Valve. I replaced it last night the light went away.

However the sputtering problem is still there. I've noticed it a lot more now, so when i come to a complete stop the car doesn't choke or have any issues. not until i step on the gas the car seems like its choking once it passes 20 mph its fine up until it reaches about 40 mph it seems to be choking again. If you really step on the gas pedal the engine will rev high but the car will drive (move a little faster instead of sitting there having it choke and not move).

I'm fresh out of ideas and no more check engine light, i guess my last resort is to take it to the dealer.

Any one have any ideas?

[bezerk19]

Originally Posted by bezerk19

Well I had a chance to take it to Autozone, they said its code P404, the problem causing the Service Engine light was due to the EGR Valve. I replaced it last night the light went away.

However the sputtering problem is still there. I've noticed it a lot more now, so when i come to a complete stop the car doesn't choke or have any issues. not until i step on the gas the car seems like its choking once it passes 20 mph its fine up until it reaches about 40 mph it seems to be choking again. If you really step on the gas pedal the engine will rev high but the car will drive (move a little faster instead of sitting there having it choke and not move).

I'm fresh out of ideas and no more check engine light, i guess my last resort is to take it to the dealer.

Any one have any ideas?

Looking at some other postings online some people are pointing towards the catalytic converter, is it real difficult to replace this part? I've seen it selling at Autozone for $300 and Midas charges about $400 for parts and labor. I just don't want to spend that much money and find out thats not the problem.

[bezerk19]

Originally Posted by bezerk19

Looking at some other postings online some people are pointing towards the catalytic converter, is it real difficult to replace this part? I've seen it selling at Autozone for $300 and Midas charges about $400 for parts and labor. I just don't want to spend that much money and find out thats not the problem.

FYI, I ended up taking the car to the dealer and the problem is the catalytic converter, they tested this by removing the O2 sensor and running the car worked fine, once you connect the O2 sensor the car has the same problem, which lead them to believe that the catalytic converter needs to be replaced.