So what's the secret behind removing the O2 sensor screwed into my rusted exhaust manifold?

PB and Knock-R-Loose has not phased it....I'm out of ideas and i dont want to bring out the breaker bar in fear that I will break something.

I had to weld a new nut to the top of the manifold when I
took mine out, and then I found out it didn't need changing

Why do you want to change it? running bad/rich or just because?

Wild

It may not need changing...it's 21yrs old and looked like an easy change...I was wrong!

It may be just fine...the engine is not running well... Doesn't respond well to the throttle lever ...sputters then backfires out of the air intake manifold. Can't adjust the TPS to the book because the throttle lever never touches the stop screw so can't use the .012 or any other specified feeler. It ran better before I started an endless pursuit to figure out the "cold idle" that has "dead spots" in throttle response before it's warm. I've replaced the AIT and CIT... I did have a 4:4 check engine light which is TPS adjustment...the check engine light isn't on anymore but it should be! new plugs and wires...I can pull a wire on each plug and the engine responds as it should...guess it's an air problem ?? It's fuel injected

Have you heard a backfire at the intake manifold before?

I have a bad TPS, it doesn't cause flat spots, it causes an off
idle dead spot like no accelerator pump, I even removed the
TPS and it runs ok, just that flat spot.

The 8V TPS is more of a switch to tell the ECM the throttle position
off idle and WOT, but it isn't a linear resistance like most TPS sensors.

I would look at the MAP sensor and any blockages in the hose leading
to it, or holes/breaks in that hose.

Have you checked the timing and firing order? 1,3,4,2, rotation clockwise,
timing set about 8* BTDC your truck may vary but it should be good enough
to run right

Wild

Alright so I found the MAP...and when the hose is disconnected from the manifold it runs like a champ...smooth and revs perfectly to my un-trained ears.... when the hose is connected to to the MAP it sputters and backfires everytime and all the time.   I can put my finger on the hole on the manifold where the MAP hose goes and it does slow down idle but idles and revs like a champ.  so -- do I even need a MAP sensor?  Is this a sign that the MAP sensor is bad and should be replaced or is this a sign that points to another problem? I didn't connect the (3) 1.5v batteris and a Volt meter and vacuum guage and test it that way -- I can if needed ?? This is awesome though -- can't beleive it's that. And the hose is not stopped up. it's a $300 part (depends on where you look -- Rockauto.com has it for $85 but they have a weird website) but the sammy can run again -- well if that's really the problem.

Should I have a Tracker MAP sensor or a Samurai MAP sensor?  There are generic MAP sensors at Autozone but you have to know how many "bars" you need.  They have sensors from 1 to 5 bars....

The timing is set to where it's always been set according to the mark on the bolt (doesn't mean its right ) and i'll have to leave it be  since im missing my belt cover with the number guide... it's ordered though.  Only 9 more days until it arrives...LOL

 

Well it could be bad, but I wouldn't buy a new one, you should be able to get
a used wrecking yard one cheep for testing and replacement

The fact that when you pulled the hose from it and the engine runs better
kind of shows that it is working, but it could be out of spec

When you pull the hose it sends a need more fuel or enrichment to the
ECM, (low vacuum) and it responds with more, so you have a lean fuel
condition under normal conditions when it's connected, that is your real
problem, when I disconnect my MAP my engine runs rough and sputters,
because it's too rich.

Try pulling the O2 sensor wire and check it for a small current, (engine running and hot)
I think it's in the milivolt range (sensor side wire) or might go to 1/2 V that would tell
you if the O2 is working as it sends a + or - V signal depending on rich or lean exhaust
conditions, and the O2 might be bad and the computer is stuck with a thinking rich because
the O2 is sending a rich signal to the ECM even though the mixture is in fact lean, and you
pulling the MAP hose is fixing this lean condition

Wild

finally got the O2 sensor off and replaced it.   For about 4 mins the engine ran smooth and as it should with the MAP hose connected to the motor... I took the map hose off the motor and it ran worse... so i was like yea the o2 sensor really was it --  Then after 4 minutes it ran like crud missing and backfiring with the hose on the motor...so unplugged the MAP hose from the motor and it ran "as it should".....grrr!!  

I dunno -- my cousin is talking like it could be a burnt valve(s). But my cylinder compression is 180psi x 4 and it jumped to 180 by the 3rd turnover in each valve.  I hope its just a MAP sensor issue or even better a cheaper sensor!  I can test the MAP sensor like in the books... (3 1.5v batteries, a volt meter, and a vacuum.... ) if that will help

tomorrow he's bringing his diagnostics computer over and going to run code....

And the timing may still be off -- no way of really knowing until I get the timing cover with the numbers on there.... so im keeping my fingers crossed.

Well it would take about 4 min for the O2 to get hot enough to work,
so back looking at the MAP as a problem, go ahead and test out the
MAP to see if it's out of spec, I don't think you need to throw in timing
to the mix as well as everything else that's going on, eliminate 1 thing
at a time so you know when there is a problem with what you did

Wild

K will do. I was doing cartwheels for the first 4mins...lol.

Do you know where the diagnostics plug-in is on a 90' Samurai. We looked and couldn't find it...is it on the ECM ?

On my 89 Kick it's over by the battery, and you just use a paper clip to get the CEL to flash codes

Crummy i have no codes! I have a white connector pin looking thing by my battery...that may be it!

Codes don't just flash up, they need to be coaxed with by shorting the diagnostic terminals

I think it is a 4 pin plug, and should of had a cover on it to keep dirt out

Right now I get codes by putting a  yellow 20 fuse in the lower right slot.... unfortunately i'm getting 1:2..... which is everthing is OK!

There is a way to get more codes from an ODB1 other than the fuse in the fuse box?

Found it!  Let's hope the fancy dignostics computer picks up codes that aren't flashing on the CEL

  That's what I was thinking of, my truck isn't at my house so I have to go from memory