three things..

[mastershake]

1. i made a thread a while ago mentioning a pending p1133 code (upstream o2 sensor insufficient switching or something) that pops up every once in a while. since then, i've noticed that it only happens on the highway when the car's been running for 10-15 minutes. i looked at the o2 sensor reading and its perfectly normal at idle, driving on side streets, and the first 5-10 minutes of highway driving. however, eventually the readings are only switching between 500 and 800 mVs. anyone know what could be going on here? (and no i'm not looking at the post-cat o2 sensor :P)

2. my ultragauge is showing the engine going into open loop for a couple seconds as im getting off the highway. is this normal??? (and could it be related to the o2 sensor problem? o.O)

3. has anyone with the 4t45-e had their transmission rebuilt at a shop? if so how much did it cost? i just want to know what i should be expecting if my tranny ever shits out on me xD

[[ion] C2]

1. get a new o2 sensor, it's not that much

2. of course it's normal

[mastershake]

I replaced it less than a year ago, although with a Bosch. Guess I'm going with ac Delco then lol

[[ion] C2]

doesn't matter Bosch O2s are fine

[mastershake]

so then i'm assuming the o2 sensor i bought was a bad one then... but would that explain why it's only happening on the highway and not anytime else?

[[ion] C2]

that's where you're cruising the most and the O2 sensor readings remain more consistent for a long period of time, giving the PCM more data to determine that the code should be displayed

you probably either have an exhaust leak, poor wiring connection, or a bad O2

[mastershake]

but it's ONLY running rich on the highway. even cruising 45 MPH down a side road, the o2 is switching between 0 and 900. but like i said, going 70 on the highway, it's a constant 500-900 range. if it IS the o2 sensor that's bad, i want to know why the hell it only screws up on the highway xD

[[ion] C2]

you need an HPTuners datalog and watch all the graphs

[mastershake]

500 dollars isn't really an option at the moment :P

even though the ultragauge has a slow frame rate, i can still tell it's running rich because it doesnt even TOUCH below 400 mV on the highway.

also, just got home from work, parked the car and revved up to 2k rpm for about half a minute (to recreate cruising on the highway) and the o2 switches PERFECTLY LIKE IT SHOULD..... but is still running rich on the highway.


WHAT IS WRONG WITH YOU CAR???