Managed to replace both of the front O2 sensors (O2S) and the knock sensor (KS) this weekend on my '96 (have been getting codes for all three for months now - just been lazy - but just failed emissions so...) and have a couple of comments to potentially add to the sticky "How To's" (note: time estimates do not include trips to the hardware store to get tools - or beer breaks for that matter

1) Front Left O2S (towards the radiator) - difficult to get at for sure - you've got to drop the driver's side plastic skirting (several phillips/hex bolts) to provide a path to the sensor and you'll likely end up jamming your arm over the engine support arm to reach the socket. Because of the tight space btw the end of the O2S and the engine, I had to put the O2S socket over the O2S and then connect my socket with a 1-1/4" extension to the O2S socket - couldn't manouver it in place w/ it all in one piece and w/o the extension I couldn't get the O2S socket all the way down on the nut to use the socket - hard to explain but get in there and monkey around with it and you'll see what I mean. Harness snap removal, harness feed, and insertion - that was all pretty easy. Time: ~1 hr

2) Front Right O2S (towards the firewall) - really easy to get at the sensor - had it off in no time. The b!tch of the process was snipping all those plastic connectors to remove the wire harness. I have no idea how ya'll get your hands in there to snip these - major PITA. Ended up having to snip the O2S wire to get it out I was also unable to route the new O2S *exactly* the same way as the old one but hopefully I got it close enough to the original path to prevent heat/mechanical damage. Time: ~1.5 hrs.

3) KS - couldn't get a wrench on this with enough torqueto pop the bolt to save my life - my hands are pretty big and the "bloody stump" comment was pretty much where I was heading - so it was the ratchet/extension/swivel socket approach that did it. What worked best was to just buy the darned 12 mm swivel socket (only $9.50 @ Sears) - the swivel adapator + a 12 mm socket seemed to add too much length for the socket to bite well on the bolt. BTW, be sure to use a 6pt socket on this - if you round that bolt off using a higher pt socket, you're hosed for sure. Got the bolt out w/o dropping it and re-insertion wasn't as bad as I thought it would be. Was even able to get the torque wrench out and tighten to the proper ft lbs torque (the variance from the use of the extension not withstanding). Time: ~45 mins

Car seems to run fine again - no codes - will check mileage to see if it improved. Just happy to pass emissions at this point...

 

Wow it only took about half an hour to do my front and rear 02 sensors in my driveway. It wasnt a big deal for doing it for the first time on my car. The knock sensor is a pain but its actually pretty easy as well once you get to do one or two.

 

that's scary to read on the 02s dude ... i gotta do it now, have a CEL for 02s

 

Well - I must admit that I do work pretty carefully (slowly) by most folks standards. I'd rather take my time the first time to be really sure its right so that I won't have to mess with it again. YMMV...

 

goodthinking, performance gains?

 

Congrats on your success and thanks for the helpful info.
I actually took more time than you did when I did front O2 sensors. I couldn't get one in radiator side off and gave up. I want to try your method when it gets warmer.

 

i have a cali spec... the o2 and KS writeups just turn me off from doing them.

 

I'm probably accelerating a little faster but not enough to really make the effort worthwhile just for that. In fact, i've noticed a bit of a mpg *decrease* that I've got to figure out. Not sure if the computer needs a bit of time to interpret the new data and make the appropriate changes in the fuel/air mixture - anyone konw if this is the case?

 

As long as you reset your ECU after you did the job you will be okay. After about 200 miles check the ECU even if there is no light on. You should get an 0505... meaning everything is fine and dandy in ECU land.

Give the car those 200 miles before you start measuring gas mileage.

 

or just leave your car sit at idle without touching the trottle for about 15min and it will run its own stuff and then you dont need to wait the 200miles to get results

 

Sounds like a plan - thought I had cleared the ECU after the step but the light was still on so I guess not. Will pull that one,and see what's what, reset and give it a couple of hundred miles and pull the code again.

Thanks.

 

Took a snap of my old and new O2 sensors side by side (old on the left). They look fairly different to me - are all the new OEM O2 sensors a bit different from the originals?

 

good job !! can anyone answer post 12?

 

It appears that you're old O2 has 3 wires, while the new one has only 2? Maybe it's just hard to tell from the pic. Sure you got the right O2's?

On my CA 99 Max, two O2's have 3 wires, and the other two have 4 wires.

James

 

I don't understand why they have 2 wires, maybe at the connector it goes back to 3. Kinda like hte KS it has two wires, but at hte KS it only has 1.

 

Pic doesn't show the 3rd wire - it's there but not shown clearly.

I was more referring to the design of the sensor end - it's completely different looking than the old one in that it has several holes instead of the slits. Also, the "nut" portion of the sensor is approx. 2x as thick as the old one - maybe both of these are improvements on the old design??

 

i dunno if why they did that but mine works fine so thats all i care about

 

Aftermarket suppliers often make different looking O2 sensors. The physical apperance in items such as this does not matter (usually). What does matter is the number of wires adn the electrical readout. You should be just fine.