98 Z28 totally stock. The O2 sensor appears to be only slightly changing between 295 and 315. The vehicle has great power and runs awesome. Replaced sensor and now it shakes or vibrates during acceleration. He's out of town and wonders what would cause this. Does anyone have ideas?

 

Why did he replace the sensor? Unclear - which sensor is stuck between 295-315, the old one or new one? What diagnostic work did he do?

What brand is it? I see people buying ultra-cheap Chinese trash and expecting it to work.

Did he install it correctly, not using any aftermarket anti-seize or tape?

 

It's a Bosch. He was able to see it fluctuating on some scanner he owns. It's the passenger front one. I think he had a code on that sensor. It ran fine before replacement. The new sensor had the anti seize applied on the threads.

 

Just for my knowledge.. anti-seize on narrow bands is a no no huh?

 

While standard anti-seize should not be used, typically new sensors come with CONDUCTIVE anti-seize already applied. I think that is what he meant when he said "The new sensor had the anti seize applied on the threads." You can buy anti-seize specifically for O2 sensors.




My question would be why not an AC Delco sensor? I have never put a Bosch in an LT1, but based on comments posted here over the past 20+ years, Bosch sensors do not always yield good results

 

My 1st thought was that the brand of sensor could be the issue. I always buy Acdelco parts for my Camaro unless there discontinued. He said watching the sensor on his scanner it acts exactly like the old sensor. It was only $20 so that's probably why he got it. Thanks for your input. Hopefully this helps him and others learn the lesson that cheaper isn't better. Especially on these sensors.

 

Sound like a Chinese counterfeit part.

 

That makes perfect sense. When I said anti seize I really meant the stuff that comes in the package in a little tube or pre applied on the sensor threads. Below is from the a website. It just needs to be sensor safe.
Use anti-seize compound to coat on the sensor's threads (some oxygen sensors have the anti-seize compound applied at the factory)

 

Does anyone know if the acdelco sensors are Ebay are possibly counterfeit? I have purchased a few items online that appeared to be OEM but the box they came in was very cheap and the product didnt work correctly.

 

Go to RockAuto and grab a GM Genuine one. I didn't see an ACDelco one....they used to offer them, but it appears that GM validates the GM Genuine brand. Seems as though ACDelco and GM Performance fall under the same umbrella.

https://www.genuinegmparts.com/

 

Interesting issue with an AC Delco part sold by Rock Auto in this thread - not an O2 sensor, just an ICM. Chinese parts in AC Delco box labeled "Made in USA".

https://www.camaroz28.com/forums/lt1...t1-icm-888931/

Rock Auto shows the AFS75 O2 sensor (part # from Shoebox) under manufactured by AC Delco search. Confusing on the AC Delco vs. GM.:

https://www.rockauto.com/en/parts/ac...29+sensor,5132

 

That's interesting. I haven't had any issues with ACDelco parts from RockAuto. However, strange that the part would have made in China on it and then the box have made in USA. I bought both my pre and post cat ACDelco O2 sensors from RockAuto, but that has been several years ago. If I had to go with another brand other than ACDelco or Genuine GM, I'd try Delphi or NTK. If I recall correctly, my wideband O2 setup came with an NTK sensor, so I think their O2 sensors in general are pretty good.

Given the above, might not hurt to order one from the Autozone or O'Reily's if possible. That way it would be easy to return if something is amiss.

This is not related to O2 sensors, but just new parts for old cars in general. ScannerDanner had a Fox Body Mustang giving all kinds of ignition trouble and turned out it was something wrong with how the new replacement part was manufactured. After around 3 or 4 modules and none of the new ones working, I think they got one from Napa that finally worked correctly. It's a very similar story to what is happening with the Opti-Spark now. Here is the resolution to that issue....I feel his pain on this as it was a tough one to fix.