1Qwik94Z

(Long Post..appologies)
My car is acting up and i think it may be some one of the sensors..among other things. I have made a couple posts and no one can really answer me straight forward. First off..Cat is hangin on by a thread (almost literally)...and since i have been driving it this way the car sputters really bad. Can I just rip off my Catalytic Converter until i get a new one? or would this cause some internal damage (possible warping of the valves or something)?
If its not because of the exhaust leak at the Cat..it could be plugs and wires, feul injectors, or the fact that my K/N air filter keeps falling off and I just leave it sitting down inside when it falls off (PITA putting on and keeping it on).
These would all just be coincidental reasons my car is now acting up..being they just happened as im driving my car like this. But i think it could also be some sensors. I did a thorough search of my engine tonight, and i found a few sensors im not sure what they are.
1. passenger side, on engine block, inbetween the starter and exhaust pipe (where it meets the exhaust manifold) if you're looking from the passenger side front wheel. What is this sensor and could it cause problems if bad?
2. there are only two O2 sensors correct? I found one on the exhaust manifold on the drivers side (fairly easy access) and one on the passenger side, just after the manifold meets the exhaust pipe (where they join). At the parts store, they said you should buy two, im thinking these are the "before" and "after" sensors they are referring too?
3. if you're looking at the engine from above it..the sensor on the very back of the intake manifold(near the driver side fuel rail). what is this one for and can this cause problems if bad?
4. looking at motor from driver side (if you're standing at the driver front wheel)...on the engine block inbetween the first two spark plugs and down just a little. At first..thought this was one of the O2 sensors, but im pretty sure its not now..after seeing an O2 sensor at the parts store. What is the function of this one and can this cause problems if bad?
5. again.looking from the top of the motor with driver side on your right, the sensor located between the passenger side feul injectors, directly behind the second fuel injector. Again, could this go bad and what is it?
I think thats it..didnt see any others i wasnt sure about. I hope someone had the time to read this thoroughly and knows what atleast some of these are. Im hoping a simple sensor is whats causing my problems. The O2 sensors seem to be the most expensive..and were not replaced when I had my engine rebuilt. Thanks in advance and as always, appreciated!

shoebox

It would take a whole book to answer "can this cause problems if bad?" That's why they have service manuals. Better to try to accurately describe your problem, than to try to troubleshoot in reverse.

You only have 2 oxygen sensors on a 1994. There are pictures of most everything on my Tech Page. When describing locations, left hand and right hand are from the perspective of sitting in the car. LH is driver's side and RH is passenger side.

Most problems can be easily solved, but it can involve using a scan tool, data logs and the knowledge to interpret the data.

Fastbird93

Not sure, kind of vauge....maybe Knock sensor??? Anyone?

Those are your Oxygen sensors, and being a 94 you should only have two. The OBDII cars with the dual cat setup got the four O2 sensor setup.

I think you're speaking of the EGR valve, and if it's bad it could cause a low RPM stumble.

That's your Coolant Temperature Sending Unit for the gauge on the dash. No biggie.

That's your EVAP Canister Purge Solenoid. Not a very common issue, but could possibly take a crap and purge the EVAP canister at the wrong times, allowing fuel fumes into the manifold. SHOULD throw a code though.

As far as your problems go, you should get your cat patched up, but it won't hurt you to drive without it (unless the cops see ya). I ran around for a couple weeks once with no cat on the car. Not a huge deal as the opening in the exhaust system is well after the O2 sensors.

It's not from your K&N filter falling off either. Granted you don't want to suck something into the motor, but it's not going to cause a driveability issue.

How new are the plugs and wires??? What you might want to try to do is get the car on a scanner of some sort to actually see what's going on. Short of that the best recommendation I could give would be to start with the basic tune up items, being Plugs, Wires, and if that doesn't help maybe try the O2's.

Injuneer

The best way to try and sort out driveability problems is to do a PCM data scan, using logging software like FreeScan (the price is right) or TTS DataMasster (free for up to 20 uses). Other than that, you are just guessing.

It might not matter, because leaving the air filter off could screw your engine up pretty good, maybe contaminate/damage the MAF sensor, excessive wear, etc.

Loadre

First thing that came to mind with me was a piece of debris got sucked up since you're not running a filter and might have taken out the MAF.

1Qwik94Z

thanks for the response guys..i think im gonna rip off the cat (its only gonna cause more damage if the thing falls off into my rear tires..lol)
I think im gonna get it to Denver to have a friends uncle (certified mechanic GM)...and see if he can pick up a problem on his scanner. After replacing the CAT..Ill put in new plugs and wires..and possibly look for a good deal on the O2 sensors.. But before replacing anything (expensive that may be good)...Ill have it scanned for sure.
Fastbird93..the stumble is at the lower RPMs around 2k and up to maybe 4...at WOP its not as bad..but does do it somewhat. I may look into the EGR Valve..are they expensive? And 'COULD' this cause a major stutter like is happening? I also felt I shoud note..it does not stumble at idle..it remains around 880-900 where its set. So Idle is good. So Im thinking its something that is effected when actually applying fuel/air...would that eliminate anything (lol probobly not)?Thanks again guys and yes, i know I should use a service manual..when I moved I lost it so this is my electronic Service Manual