I have a 96 LT1.

According to the parts store I,m suppose to have two upstream and two downstream on a 96. If you go to 95 they only list two upstream for 95 which is OBD1.

Which is which?? My 96 which is OBDII and I know it is only has TWO sensors mounted on the end of each Pacesetter long tube Header. Nothing else no other wires no plugs that arnt plugged into anything. The PCM is throwing O2 codes ( sorry dont remember which ones.) has since I owned it and now the car is running rich and missing slightly when warmed up. Thanks in advance for any help.

 

Your 96 originally came equipped with four O2 sensors, two pre-cat and two post-cat. The post-cat sensors are only to confirm that the cats are working properly. Many times they are deleted with O2 simulators when cats are deleted. Are you the original owner?

If there are codes, you need to have them pulled. That's what they are there for.

 

Agreed on the codes, not everyone has access to a FREE code reading and I refuse to step foot in Auto Zone.

No I am not the original owner, the car has long tubes, if the o2s were once there then were did they go?? Ive have had this motor out of the car, there are no extra wires or plugs just the two o2s that are in the end of the long tubes. What I,m saying is THERE NOT THERE and I didnt remove them.

 

You can get an OBD-II code reader for about $40.

Not sure I get your point. If its a 96 model year production vehicle, it left the factory with the 4 O2 sensors, and the wiring harness to hook them up to the PCM. Either someone removed the wiring, changed to a harness from an earlier year, or modified the harness to delete/hide the sensors. The after-cat O2 sensors would have been in the stock dual-cat Y-pipe, which is long gone, if you have long tube headers.

But if you don't want to have it scanned, you aren't going to know.

 

To further clarify:
Your 96 came from the factory with 2 upstream and 2 downstream sensors.
Whoever installed the long tubes removed the 2 downstream sensors (they just threaded into the pipes and plugged into the harness). It would be very easy to just snip the wires off where they came out of the harness and the stubs would be difficult to find. Your inability to see the wires is irrelevant, they came from the factory installed and working.
AFA the codes, you MUST scan to see which ones are present. If the PO did not have the downstream sensor P-codes deleted in the PCM, they will be present. It will take a tune in order to delete these codes, nothing else will do it.

 

Just curious.... why do you feel you have to "clarify" what I post - seems to be your new habit?

 

I'm sorry you took my response as "unwelcomed." But being stubborn about having the codes scanned won't help your cause. I see plenty of guys just like yourself come onto the forums complaining about issues that have an SES light on, but for one reason or another, they don't have it scanned. I never said anything about a "FREE" code reading either, so why the hostility?

If the light is on, it's telling you there's a problem with a specific part of your vehicle. Why guess?

Your question has been answered. Good luck.

 

I,m sorry too. Not everyone wants to or just can spend $40 on a scanner. I dont know what your finacial situ is but mines not the greatest and would hate to loose the car on account of the economy.

I just know that I,m suppose to have 4 sensors and I only have two.

What I guess I,m asking is then, is there a way I can make sure I have the two UPPERS and not for some dumb reason have the wrong ones??? And if I get another new Upper and replace the one I havent replaced yet I should be ok. I do get o2 codes but there downstream codes as well as Upstream codes. The SES light is always on since I have no cat and I,m not going to spend the money to get it programed out. Sorry not everyone is as SMART as some of you. Thats why we ask questions to find things out we dont know, if you dont like it dont have a LT1 questions forum.

 

You complain about your financial situation, yet you refuse to get it scanned for free? Why? You come on the forum asking for help, and thats what you got.

The easy way to determine which sensors you have are to just get under the car and look.

You seem convinced that your SES is on because of the lack of cats, but that would only be the case if you still had your rear O2s hooked up. Once again, have it scanned.

I'm not claiming to be the smartest person on the forums, but you have the tools and information you need to answer your questions, yet choose not to use them. Quit being so stubborn.

 

I do get o2 codes but there downstream codes as well as Upstream codes

I had it scanned I dont need to tell you the codes as I already know what the scan told me. Ive just never ran into to a car that had the o2s just cut and removed. This whole time I just thought it was like the OBD1 system which only has two upstream.

YES my ses light is going to come on regardless as I know this form previous scans which says cat malfunction basically your cats are bad. I DONT HAVE THEM so I now it wasnt programmed out. So I,m not going to scan it everytime the ses light is on as ITS ALWAYS ON FOR THIS REASON.

All I needed to know really was that I am suppose to have 4 o2s on a stock setup, I did not put the long tubes on they were there when I bought it. The two o2s I have are the upstream ones as yes I do look under my car ON OCASION as you have supposed i,m lazy and didnt look.

Right now I,m going to go out and change the other sensor as the other one is new. As for asking any more questions on this board I,m not going to do it as you just get crap from everyone.

Injuner thanks for your help none of this is pointed at you you do nothing but help people on this board everyday and I thank you for it. I,m new to LT1s and having to mess with PCMS and o2 sensors, I come from simple carbs and brainless systems.

 

You indicate you didn't point anything at me, but I'm the one that suggested a $40 scanner. I just can't understand why anyone would spend money on a great car like a 96 SS, and then refuse to spend $40, or take it to a shop for free (doesn't have to be Auto Zone) to get it running without an SES light. I don't understand your hostility toward the other person who was trying to help you either. I pretty much agree with most of what he said.

I guess it doesn't really matter, since you indicate you aren't going to post here any more. This site is really changing, and the more I see of incidents like this, the more I think of moving on. I'm already spending more than 1/2 my time on another site, that seems to be free of all the petty bickering and "attitude" that seems to become more common on this site every day.

 

I dont know where you live but I cant just walk in to any shop and get a free scan. I have to schedule it anywhere I go. As far as Auto Zone the one I have you walk in the door and you literally have to say HEY I NEED HELP OR I NEED THIS and then its like ok give me a few minutes I have an ich.

And why does everyone think scanning your codes is going to tell you everything you need to know abut every situation. IT DOESNT. Ive sean cars run like they were on 5 cylinders and no code at all. I,m not going to run to the code scanner every time something is wrong, and I dont know what scanner your talking about that is $40 bucks, the cheapest ones any auto parts store offers be it auto zone OrileysNapa is over $100 and yes I ask around today since you mentioned it. When I said Code reader for $40 they thought I was on crack.

As far as my question on the 02s it was answered already way before all this got out of hand.


But if you don't want to have it scanned, you aren't going to know.

I dont understand what you mean by this, scanning it isnt going to tell me what happend to the rear 02s. Ive had it scanned and all it says is basically that there malfunctioning. I was not aware that I needed four and that there were two up front and two out back, I just figured I had two, one upfront and one outback. I was wrong. I never said I didnt have it scanned all I said was that its going to throw a code when there are no cats, so I cant jump to the conclusion that OH the SES is light is on LIKE IT ALWAYS IS I better have it scanned everyday to make sure theres nothing wrong.

 

injuneer:
"the more I see of incidents like this, the more I think of moving on."
I hope you and the other stalwarts of the 4th gen don't leave. The older forum would die if that happened. BTW ... about your screen name, is it from the old cartoon with the caption "Yesterday I couldn't even spell injuneer, now I are one!"?

 

Yes.... that was carved in a couple of the desks when I was in college (NJIT - but in ye olde days when I went there it was NCE). Couple that with the Pontiac "tin indian" and it seemed like a logical choice.

I actually had a guy on this site tell me he was 1/16th native american, and was offended by my screen name.