Ok, 96 Blazer LT 4.3 4L60E NP-233...blah blah blah (if more info is needed ask)

I bought the Blazer with a bad transmission, I knew it was bad, but I got it pretty cheap. Trans had no R, 2nd or overdrive, but still ran and drove. I got a replacement transmission for it and put it in yesterday. Now, I am experiencing a come and go missfire, and a slight vacuum leak somewhere. Also got a code for O2 sensor bank 2 sensor 1 high voltage.

I know I have an exhaust leak at the rear of the center section where we pulled it out and I will get a gasket for that. All my O2 sensors are plugged in well and no wires are crimped or cut. Which one is bank 2 sensor 1? Book says after the Cat BUT...there is no O2 after the Cat LOL. Also getting a code for multiple / random miss fire. Could the vacuum leak and exhaust leak be causing these issues? Where to start....

New trans works great BTW

 

I have seen a few people in the past get the wiring harness that goes across the back of the engine caught between the engine and transmission so you might want to check there to be sure.

B2S1 is the sensor closest to the passenger side exhaust manifold. Your truck should have a total of 4 O2 sensors...

 

It does have 4, one in the DS manifold, one on each runner down to the collector, and one right after the collector.

Though we did make sure to pull the harness up and wire it out of the way before lifting the new trans up in there. I'll check it again,
Thank you

Also, does anyone have a diagram or can tell me where the three vacuum lines on the transfer case run to? One has been spliced before and I'm having problems locating where it goes.

 

Here is what your O2 sensors should look like:

 

So, it's been a few days and still driving it around like this. Sometimes it gets really bad, and has NO power at all, but if I put it to the floor it will go. After flooring it a couple times it will clear out and stop missing...then it drives fine until the next time it's driven. Then the same problems all over again.

 

UPDATE:

nOOb move, I blew the teeth off the transmission fluid pump yesterday. This gave me the chance to pull the trans back out and look for the other issues though. I had a vacuum leak causing the missfire, fixed that. Put a new pump in my trans, and replaced a few other things. Tomorrow I am going to adjust the shifter cable if the bracket is not bent, I can't get it into park now. Thats no biggie though.

Thanks for the help!!

 

I was wondering if this diagram is used for a 2001 blazer?

 

No. In your case, there will be nothing where the B1S2 sensor is noted on the view above.

 

Thank i am getting the code P0155 so i wanted to change that one out first. I see which one it is.

Thanks,

 

Sooo, I blew another pump out....the first one was my fault for the torque converter sliding forward when we put the trans up on the jack. But this one, I made SURE it was all the way on when I put it in. About 200 miles and it shattered the pump to pieces. Any ideas on what might be causing this?