buying new o2 sensors... are there any recommended brand to go with or does it not matter. not sure if it's like spark plugs, so far my truck hates bosch. also another question i have is how many o2 sensors does my truck have. i haven't been underneath the truck to check. some places i see 2 before the cat and 2 after some say 1 before and 1 after. i'm a little confused

 

yes bosch- upstream sensors $50 @ autozone or advance-phil

 

go with bosch 02s and you only need to replace the sensors that are before the cats there will be one on each side, you also have two one on each side downstream of the cats but those dont need to be replaced unless they actually fail and throw a code. good luck it is pretty tight working area and a pain in the ars.

 

Of course, it should be asked WHY you're considering rep[lacing the sensors.

Many sensors are replaced due to a faulty diagnosis and do not repair the original fault.

Steve

 

Someone on here suggested i should change my o2 sensors bc of a couple new mods i may be adding which are small things, programmer, efan and high output coils

 

If it's a 97 and they are original, I'd replace them at any rate.

They gradually go bad, and won't throw a code until they've gotten really bad. This is from experience...wonky A/F ratio on old sensors that calmed down with a sensor change. My opinion, but every 40K miles or so is when I change mine.

Perhaps a bit over-zealous, but A/F ratios are super important on a blown application so I'd rather not push things. But even for a stock truck, I THINK that keeping them in top shape helps things run optimally.

But if they are relatively fresh, I don't think you need to change them just because you've added a few mods.