3800 need some help

[gtpdriver7]

Whats up guys,

alright heres my problem. when i turn my car on and its warming up everything is fine, but when it warms up the rpms go up and down from 900 to 500 to 900. then yesterday i was curious and i went WOT and my boost guage only goes half way. also when im driving it doesn't matter speed i am at when i let off the gas its goes down to 500 rpms and stays there until i get on the gas again. also when the rpms go up and down when they go down to 500 rpms all of the lights dim. anybody know what the problem is?

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[Toasty]

Whats up guys,

alright heres my problem. when i turn my car on and its warming up everything is fine, but when it warms up the rpms go up and down from 900 to 500 to 900. then yesterday i was curious and i went WOT and my boost guage only goes half way. also when im driving it doesn't matter speed i am at when i let off the gas its goes down to 500 rpms and stays there until i get on the gas again. also when the rpms go up and down when they go down to 500 rpms all of the lights dim. anybody know what the problem is?

[/b]

no SES light? if there's an SES light, i'd point to an 02 sensor, but if not, i'd check for vac leaks to start with, and go from there.

 

[gtpdriver7]

my ses light is on. yea ill take it in to get checked for some vac leaks. if i have no cat do i still need an o2 sensor?

 

[PANDA]

There are two O2 sensors, one before the downpipe and one after the cat. Im told the one after the cat is useless.

 

[Sinister Drag Designs]

the one after the cat is to report the condtion of the cat. its not needed except for emissions, you need to have your rear o2 activate one of your cars drive cycles. i just found out you can get away with not having one drive cycle working.......but on most cars the EVAP never triggers its cycle so thats the one that you get away with.
so no the rear o2 is not causing your problem
let us know what code you popped

 

[Toasty]

yah, you dont neccessarily need the rear 02, but the front could be flaking.