Your problem sounds somewhat similar to the problem I had w/ my VX. Mine stumbled and almost died when slowly accelerating. When I accelerated hard, it was ok. As soon as I let up on the gas it bucked and stumbled. Turned out that the EGR ports were clogged w/ carbon. To test, I unplugged the hose to the egr valve control assembly and blocked it off. All symptoms went away. The only thing different from your problem is I was getting a check engine light. I never ended up cleaning the ports because I would have had to remove my intake manifold. Instead, I kept the hose blocked and never had a problem after that. See the following links for info about blocked EGR ports:
The only thing different from your problem is I was getting a check engine light.
I wonder why that would set a code. The diagnostics in these 92-95 VXes don't seem all that smart. It appears to me that the ECU does a minimal test on each unit, and if it seems to be there and responding, it kinda shrugs and says "OK." But maybe I'm missing something ...
Thanks for the suggestion. Pulling off the hose to the valve is an easy test to try, so definitely worth it.
I have to pass I&M here. However, the NOx limit is 1240 ppm, which seems pretty high, so it might pass even without the EGR. (Her last test, 2 years ago, she did 46.3 ppm.)
I have a new oxygen sensor on its way, and we'll see what that does to the situation.
Thanks to everyone for the ideas and help so far. If I may bother you a bit more ...
Does anyone have a suggestion for an oxygen sensor installation and/or removal tool?
Most of the oxygen sensor wrenches I see advertised are 7/8" and say "fit all US and many import sensors." I'm not sure they'll do the job for this one. A 7/8" open end wrench fits pretty loosely on the hex. It's been living in that manifold now for 12 years, and it's not going to want to leave. I'm just about certain to round it off trying to remove it if the wrench doesn't fit perfectly.
I have some deep impact wrench sockets (no impact wrench, but a sturdy breaker bar and about 3' of galvanized pipe can bust loose some pretty tight stuff). The 22mm socket seems to be the right size, though it's not quite deep enough to fit over the old OxS, so I can't seat it to be sure. Besides, I'm not quite ready to cut the connector off yet.
I could chop off the top of the old OxS, or go buy a deeper 22mm socket, but I still wouldn't have any way to install the new OxS.
What do you use? Are the "crowfoot" wrenches any good for installation? Will an extra deep 22mm socket (preferably 6 point) do OK for removal?
If you need to remove the Oxygen Sensor and it's been in their that long, it is probably going to be stuck pretty tight. If you get a tornado porpane torch it puts out a very hot flame, which you can use to heat the exhaust around the Oxygen Sensor. You want to heat the exhaust till it's as hot as you can get it, or to where it starts to glow red, if you can.
For a wrench I purchased a 7/8 inch box wrench and then used a cutoff wheel to cut a notch in it, so I could use it to remove and install the Oxygen Sensor. You need to get a 8 sided box wrench, not a 16, so that you have all of the steel you can get, holding the wrench.
I would definitely put in all new plug's, but if they are all black like you described, then I'd go ahead and replace the Oxygen Sensor.
On the propane torch, you can also get a bottle of MAP gas, which burns hotter than propane, but attaches to the same torch head. Mine comes with about a 6' hose, which makes it real handy, but I've also seen them mounted to the bottle adapter.
They look similar to a regular propane torch, but they look like they have a silencer, like on a gun, attached to the end. They can be used for regular soldering, but you need to use the lower side of the heat range.
I used the special O2 sensor socket with the slit on the side. Not sure of the size...I can check it for you if you want. I put plenty of torque on it to get my 13 year old O2 sensor out and didn't have any problem. I actually used a breaker bar to break it loose. FWIW
Oh, you'll definitely want to get the car fully warmed up at a minimum before trying to break it loose, that's what I did. Or take the advice of the previous poster.
Thanks for the tips. I've never seen a 6-point box end wrench. I probably don't shop for tools in the right places.
There's not much detail on the d15z1 engine's OxS in my Haynes manual, but in the "general instructions" it does suggest running the engine for a while to get the manifold hot before trying to remove the sensor. So Gary's idea makes sense.
I just want to make sure I don't round off the hex on this critter. I've done similar dumb things too many times and ended up having to take heroic measures. Or worse: there's nothing more humbling than calling up a mechanic first thing Monday morning to ask if you can have your basket case towed in.
I don't think the humungous 8-pin connector on this sensor will fit through a box end wrench. I might be wrong. That doesn't matter for removing the old one (just cut the wires off), but it does for installing the new sensor.