Question from a n00b.

[GregadetH]

Hi all! I've got a puzzling problem that I'm hoping some here can solve. I've recently bought a 1988 2.3 Ranger. Please bare with me as I'm not very mechanically inclined - yet.

I bought the truck with a bad exhaust system...no cat and an exploded muffler. It was running like it had water in the gas as well as smelling of rich exhaust. I bought a universal muffler and several clamps, adapters and even muffler putty to stop the exhaust leaks into the cab caused by the placement of the pipe where the converter was cut out. I've also changed the cap, rotor, wires, plugs and IAC. It still ran like it had bad gas. Mind you, I've gone through 2 tanks of gas and seafoamed the first fill up. Out of curiosity, I disconnected the O2 sensor leading into the manifold that was in front of where the cat should be. Now the bucking and rough running has almost stopped completely and the rich exhaust smell has gone away. I plan on installing a new cat when I can. My ultimate question is if there is no cat, would the o2 sensor cause the truck to run all wonky? It ran much better once I disconnected it.

Any help is greatly appreciated! Thanks!

-Greg


Edit: The electrical connector to my o2 sensor is pretty burnt as well. What is that a sign of?

 

[SixFoFalcon]

No front (upstream of the cat) O2 sensor input means that the engine management system has no idea if it is getting the right amount of fuel. It defaults to pig-rich because that's less likely to cause quick engine failure than running too lean. So you end up with exhaust that stinks of unburnt fuel, piss-poor fuel economy, and reduced power. Get the O2 sensors hooked up again.

 

[GregadetH]

No front (upstream of the cat) O2 sensor input means that the engine management system has no idea if it is getting the right amount of fuel. It defaults to pig-rich because that's less likely to cause quick engine failure than running too lean. So you end up with exhaust that stinks of unburnt fuel, piss-poor fuel economy, and reduced power. Get the O2 sensors hooked up again.

The truck runs 110% better with it disconnected with no loss of power or smelly exhaust. Don't worry, I'm not running the truck 24/7 with the o2 sensor disconnected. I'm merely trying to understand what's going on with my truck so that I can fix it. My question is will not having a cat cause an 02 sensor to wig out and make the truck run like a camels ass?

 

[MikeInIdaho]

Yes.
You can replace the cat w/ an adequately-sized clamp-on aftermarket affair for about $75 (which I would strongly, strongly recommend doing) or get an 02 emulator that plugs into the sensor and mimics the signal of a properly functioning cat, keeping you're engine management system happy and within range.

To be honest, though I would recommend replacing the cat and possibly the o2 (if needed) with functional pieces as the factory intended. It's a federal offense to remove or fail to replace a missing catalytic converter on any vehicle so equipped from the factory. It doesn't hurt performance and is good for the environment. There are ways around using one, but why go through all the trouble? It would be just as easy (and inexpensive) to replace it. Good luck with whatever you do!

 

[GregadetH]

Yes.
You can replace the cat w/ an adequately-sized clamp-on aftermarket affair for about $75 (which I would strongly, strongly recommend doing) or get an 02 emulator that plugs into the sensor and mimics the signal of a properly functioning cat, keeping you're engine management system happy and within range.

To be honest, though I would recommend replacing the cat and possibly the o2 (if needed) with functional pieces as the factory intended. It's a federal offense to remove or fail to replace a missing catalytic converter on any vehicle so equipped from the factory. It doesn't hurt performance and is good for the environment. There are ways around using one, but why go through all the trouble? It would be just as easy (and inexpensive) to replace it. Good luck with whatever you do!

Thanks for all the input!

I'm definitely replacing my o2 sensor, sensor wiring harness and adding cat asap. I'd rather save my money and fix all of that stuff instead of dumping less money on parts that probably won't fix the problem.

 

[KELLY88]

Thanks for all the input!

I'm definitely replacing my o2 sensor, sensor wiring harness and adding cat asap. I'd rather save my money and fix all of that stuff instead of dumping less money on parts that probably won't fix the problem.

Smart move. Let us know how it turns out.

 

[midget]

Yes.
You can replace the cat w/ an adequately-sized clamp-on aftermarket affair for about $75 (which I would strongly, strongly recommend doing) or get an 02 emulator that plugs into the sensor and mimics the signal of a properly functioning cat, keeping you're engine management system happy and within range.

To be honest, though I would recommend replacing the cat and possibly the o2 (if needed) with functional pieces as the factory intended. It's a federal offense to remove or fail to replace a missing catalytic converter on any vehicle so equipped from the factory. It doesn't hurt performance and is good for the environment. There are ways around using one, but why go through all the trouble? It would be just as easy (and inexpensive) to replace it. Good luck with whatever you do!

Where can I pick up said part and what does it normally run? My offroad truck needs to have the cats removed and it also has a dead spot in the rpm range. I dont street drive my truck just a trail runner and this would fix my headache.

 

[MikeInIdaho]

search for "oxygen sensor simulator" using a well-known search engine (e.g. google, yahoo etc) and you should be able to find what you need. good luck!

 

[SixFoFalcon]

Where can I pick up said part and what does it normally run? My offroad truck needs to have the cats removed and it also has a dead spot in the rpm range. I dont street drive my truck just a trail runner and this would fix my headache.

Just to re-iterate, if you choose to go with an O2 "cheater" rather than a real O2 sensor, make sure you only do that on the downstream (post-cat) O2 sensor location. You NEED the upstream (pre-cat) O2 sensor for your fuel-air ratios to be correct.