Missing catalytic converters on a Ford Ranger

[buickanddeere]

On old vehicles like the one in question, you are correct. But stuff from the last 15 years or so will use the rear sensors to fine tune the mixture to optimize catalytic converter operation.

Rear “ fuel cell “ sensor is measuring the exhaust and the ecm expects a fairly low voltage and reasonably steady voltage of 0.45 to 0.5V which is consistent with exhaust with low hydrocarbons .
Front sensor wonders around the 0.7V with wide swings .

 

[cleddy]

Anyone know the long term effects of running a 1999 Ford Ranger with a 3.0 without catalytic converters? I know the CEL will be on forever but what other issues might I encounter? Local shop says its $1500 to replace the cats ($1200 pickup). No state emissions checks to worry about. I know there also sensor replacements you can buy to trick the computer into thinking the cats are giving a "normal" feedback. Would the engine run lean and hot, or rich and "cool" without feedback from the cats?

Kind of off the subject but will a engine run without a Mass Air flow sensor? I have a 1986 Oldsmobile that I can't get running and blew mine up with using ether. Would like to get it running again? It would not run after neglect and sitting to long?

 

[NDIHC]

Kind of off the subject but will a engine run without a Mass Air flow sensor? I have a 1986 Oldsmobile that I can't get running and blew mine up with using ether. Would like to get it running again? It would not run after neglect and sitting to long?

Most of those older ones will run. I've had cars with bad maf sensors. Usually when they go bad the vehicle won't want to accelerate. On two different suvs I had, when it would fall on its face and not accelerate, I'd unplug the maf and it would run and drive nearly normally. Not perfect but it would get me back home, basically defaulting to a basic fuel strategy using the tps/o2 sensor/cmps/ect sensor and ckps etc. as inputs. Acronyms for sensors may vary by manufacturer!

 

[Sprint 6]

Kind of off the subject but will a engine run without a Mass Air flow sensor? I have a 1986 Oldsmobile that I can't get running and blew mine up with using ether. Would like to get it running again? It would not run after neglect and sitting to long?

Maybe, maybe not. While they will technically run (if you call spitting and sputtering running) the 80's hot wire MAF gm cars, the baud rate on the ECM is so slow, they have trouble staying running because the ECM can't switch fuel maps fast enough without a MAF input. So the engine ends up with dead spots you can land a plane in, scary pulling into traffic.

Rear “ fuel cell “ sensor is measuring the exhaust and the ecm expects a fairly low voltage and reasonably steady voltage of 0.45 to 0.5V which is consistent with exhaust with low hydrocarbons .
Front sensor wonders around the 0.7V with wide swings .

The rear O2 sensors voltage should actually be above the .5 mid point, like .6-.7 volt, as this indicates the converters are working and burning off the waste hydrocarbons, which consumes the rest of the available oxygen. Most modern cars use pumping cell lambda sensors in the front and rear locations that are far faster, and more accurate, than old style high low sensors. Modern lambda sensors in the upstream location are so fast, they can pick up cylinder to cylinder mixture variations in the exhaust pulses as each cylinder fires. Mixture fine tuning with the rear sensors is done as to not over work today's much smaller converters.

 

[UncleTom]

I watched a video of a Toyota mechanic. He said to take your Toyota out on a road and for get there is a speed limit. It warms up the cats and cleans them. I do it occasionally and it must work cause when i stopped and got out i could smell them and they were hot.

 

[Texasmark]

I watched a video of a Toyota mechanic. He said to take your Toyota out on a road and for get there is a speed limit. It warms up the cats and cleans them. I do it occasionally and it must work cause when i stopped and got out i could smell them and they were hot.

When I was a teen in high school, everything in our town was 2 miles distant or less. Mother's '51 Ford flat head V8 would get choked up every so often. Boy-son had a fix. When it got to belching and pfarting, I would take it out to the Interstate type super highway and blow it out....great sport. That would fix things for a couple of weeks before having to repeat it.