Happy Holidays,

I am going to do some preventative maintenance and want to replace my O2 sensors now that I am around 90k.

What is the best O2 sensor for our SS's? AC Delco is typically what I have always been recommended on my previous GM cars, but I see some people are running Bosch sensors here.

I have a Catless DP with a defouler, no codes for my O2, getting good MPG but again want to do it preventative so that I can keep her running in tip top shape!

(PS The search functions on these forums is junk )

 

Also just in researching it seems there is two sensors, is this true even with a catless DP? Is it on the rear manifold right before the CAT? I'm assuming I should replace both or is it like the 3800 where the second sensor is more of a dummy/back-up sensor?

 

I've used both AC Delco and Bosch sensors, both worked great no issues, as for the number that you have, I don't see two on my LT but I'm sure an SS owner will chime in.

 

Hmmm. I thought all the HHR's had 2. One upstream from the cat and one downstream.

 

My 2.2 AT 2007 LT does not have cam sensors either and as far as I can see looking under the car, there is no O2 sensor past the cat, just the one before the cat just after the exhaust manifold flange

 

I thought all cars with OBDII had an up steam o2 sensor and a down stream o2 sensor. Here is a pic of an hhr convertor you can see the port for the down steam sensor.

 

I believe you're correct. The one before the cat is to adjust the AFR, the one after the cat is to make sure the cat is working.

Ira

 

Some HHRs have the upstream O2 sensor on the exhaust manifold instead of on the pipe. I think it's manual transmission that makes the difference, but may be year.

The 2 O2 sensors actually form a 3-way feedback loop with the fuel injectors, as well as cat performance etc.

 

Reason in this case is "best""favorite" brand questions are pretty lame on any internet site. That's like A--es, everybody has one. It's really only a device to spur postings.

How many factories do you think manufacture a fairly durable product? There are way more box printers than factories.

 

Old thread but I thought I would add that:

My stock 08 5spd upstream wideband O2 is Bosch 0258 017 120. It also has the GM 12589380 part number and LSU 4.9. I noticed a couple of people said the OE O2 was NGK. Not on mine and its never been replaced.

However, I did go with an NGK 24325 replacement and we will see how long it lasts.

Symptoms:
Confirmed P2177 System too lean
Pending P2097 Fuel Trim too rich
Slight miss when driving while warming up
Rough idle warmed up that would finally throw the P2177. This rough idle went from mild to worse over about 3 months until it got BAD (but still idled.)
Slight hesitation going from steady cruise throttle WOT
Passed the vacuum leak smoke test

All symptoms now gone.

08 HHR SS with GMTU 5spd. Fully stock