I have an SES ligh on my car all the time.
I have a '98 Z with no cat. I bought the car that way from a whole sale dealer. He knew nothing of the car. Anyways, I always thought the SES light was because of the !CAT mod = no O2 simms.

Well, 2 weeks ago, I had the car jacked up to install my driveshaft saftey loop. I just happened to look at the O2 wires - and there happened to be some O2 Simms on there.

...Odd.

Now I couldn't figure out why I was getting the SES light.
I posted in the MI section, as someone offered to run a scan on my car. In this post (Paging SinisterSyclone) - SinisterSyclone was nice enough to do a scan on my car.

These are the errors the car is thowing:

Could the EGR CIRCUT cause the O2's to read wrong? Or perhaps the O2 simms are bad? What does it mean?? I how can I fix the EGR CIRCUT form being low????



Thanks for any help.
Milo.

 

Those codes are the rear 02's

your simms are prolly bad

 

I had a feeling thats what it was. Thanks!
Do you know what EGR "A" CIRCUT LOW means?


Milo.

 

Did your car fall into the EGR recall?

some of the 98 had to have the EGR replaced... could be that?

usually a low freq means its not working or something?

 

Your EGR is dead. It happens. Mine died after about 32k. Its about $125 from a dealer and dirt simple to replace.

Adam J

EDIT: Also you saw simms on there. But were they front and rear or just rear or what. You have 2 O2's on each side, 1 pre cat one post cat if you had cats.

Adam J

 

So, I will need a total 4 O2 Simms??
I thought I only needed 2 for the back...as those ones plugged into the car, and the front ones didn't.

So, with the ERG being bad - would that have any effect on the O2 simms? (Or vise versa??).


Thanks for your help everyone!
Milo.

 

P0405 = EGR "A" CIRCUT LOW
P0138 025 = HIGH VOLTAGE. BANK 1, SENSOR 2
P0158 025 = HIGH VOLTAGE. BANK 2, SENSOR 2

Milo, here's what your codes REALLY are, according to the GM bible:

PO405: Exhaust gas recirculation sensor circuit low (EGR sensor takin a dump)

PO138 025: Oxygen sensor circuit, high voltage (post-converter sensor, left bank) (o2 sensor/simm is shot, left side y-pipe)

PO158 025: See above, for right side y-pipe.

 

Thanks for clearning that up for me.

-Milo.

 

I happen to have the EGR setup from my 98 sitting in the garage. It's got about 10k miles on it since it was replaced under the recall.

$75 shipped if you're interested

 

no no no. Didn't want to give you that idea. Sorry. You just didnt specify what you had simms on. The EGR more than likely didn't cause your O2's to go bad. What more than likely caused your O2's to go bad was the offroad pipes. With nothing inline to filter the fumes comming out your engine (cats) it will foul your O2's quicker. Just pull them out and look at them, if they are black they are bad.