P1133, P0141, & little power when accelerating

[jessman1128]

I have a '96 Grand Am with the 2.4L engine.

It is throwing codes P0141 and P1133. P0141 is for the rear oxygen sensor, which hasn't been replaced since I purchased the car (1.5 years/30k miles ago). P1133 is for the front oxygen sensor, but is not one of the more common codes thrown when that sensor goes bad. I did replace the front sensor last summer.

I've also fairly recently started experiencing a lack of power when accelerating. I think that's the right terminology. Basically, I press the gas pedal down farther to accelerate and it either does nothing at all, or it accelerates some but not nearly as well as it used to. It doesn't do this all the time, it's more sporadically, but it has been happening more frequently lately.

Just two days ago I had the acceleration problem to a much more severe level. I was returning to work from lunch break and was driving down the back drive to the office going about 10-15mph when the car started to cut out on me. It didn't want to go at all, no matter how hard I pressed the gas pedal. I could barely hear the engine running during this time. Every few seconds I could hear the engine get a little louder (to where I could barely hear it) and the car would accelerate very slightly for a couple of seconds, then it would cut out again. It did this for about 30-40 seconds, then it sounded like it was going to die all the way so I just stopped and turned it off. I waited about 20 seconds, turned it back on and it was fine the rest of the way. (Fine = typical acceleration issues, not the severe ones just experienced)

Since P0141 is for the rear O2 sensor, that wouldn't be causing any of my driveability issues, would it?

I plan on pulling the front O2 sensor tomorrow and replacing it again just to see. Since P1133 isn't the typical front O2 sensor code, I'm wondering if there are other things I should be checking out tomorrow while I'm working on it. Any advice would be greatly appreciated!

Oh, and two other things that may or may not be related.
One, my gas mileage has gotten worse recently.
Two, sometimes when I'm driving on the freeway with cruise control on, when I run into construction and have to slow down I'll put my foot on the gas pedal to keep the speed the same, turn the cruise control off, then slowly let off the gas pedal to start slowing down. When I start to slow down, sometimes the engine sounds like it's going to cut out on me. It's just for a second, then it's fine after that, but it's still kind of odd.

[Scrapper]

i would've changed both O2'S at the same time....

[DepecheFan08]

I've had some similar problems on my 96 2.4L. I also had both O2 sesors replaced a couple of years ago. If I remember correct it didn't fix the problems I was having.

A few things to consider are the ignition housing, coils and plugs. Have you replaced any of those parts since getting the car? Mine doesn't go more than 15K at a time without having to replace the coil housing. Check if those parts are burned.

The way you are describing the problem, it seems that the car is either running too rich and flooding (fuel regulator may be bad), or the air intake control is at fault..or a combination of those..your air/fuel ratio.

[crazy Jim]

no response when pressing the accelerator could also be a worn throttle position sensor.

[jessman1128]

This morning I replaced the front O2 sensor. Didn't have the time or money to do the rear one. Had to take the car on a rather long trip this afternoon - 90 miles each way - it ran better for the most part, didn't have any serious acceleration issues. One thing I did notice though is a rather noticeable oily exhaust-type smell from time to time. My exhaust has been loud for about a month now - I haven't taken it in for a full exhaust inspection, although during a brief regular car inspection they told me my muffler had a few holes - which I already knew. I'm not sure if this smell is coming from that and it's more noticeable now for some reason, or if my replacing the front O2 sensor has somehow caused this smell. Also, the check engine light hasn't come back on...yet.

Anyway, that's where I'm at right now. I'm going to hopefully put some more time into it in a few days when I have more time and see if I can figure anything else out. Probably get the entire exhaust system inspected too. I'll post again if/when I figure anything else out.

DepecheFan08, I replaced the plugs/boots right after I bought the car, about 30k miles ago. Haven't replaced the ignition housing, or coils or anything like that.

[jessman1128]

How difficult of a job is replacing the rear O2 sensor for an amateur DIY like myself? More specifically, how high do I need to get the car to be able to access the sensor? Would jacking it up or using a pair of ramps get it high enough? And what about the routing of the sensor wire up to the front of the car wherever it connects up there? Is the entire wire path relatively easy to access, or does it require removing a bunch of other parts or something?