Before I post this, please refrain from giving me any environmental lectures! I'm getting ready to bolt on a new set of headers on my '92 F150, 5.0, 5 spd 4x4, and I'm wondering if I can get rid of the cats and all computer related sensors or the whole computer itself. I've had a lot of problems with the emissions components on this thing (see previous posts for the past 6 months). Most still haven't been resolved. I've just learned to live with the CEL flashing. I've had old muscle cars in the past with no computer and everything was a hell of a lot easier to work on. I know the ECM controls the fuel/air mix and I know it's probably not good to remove this stuff, but here in S.C., we don't have inspections and frankly, I'm tired of the hassle and expense of replacing sensors and cat converters. Also, what will happen to my gas mileage. I've heard it could actually improve. That would be great! I don't see how it could get worse.

 

Ok, how exactly do you think your speed density electronicly fuel injected engine will run without the computer?

 

u can't remove like any sensors there all wired into your EFI system thats why if one of ur sensors is going bad u get really crappy fuel milage, all those sensors aren't just for emissions there meant to get u the best performance outta ur truck excpet for the cat's those u can take out without having an issue

 

TTT....we CAN'T let this thread fall to the bottom. Every memeber should read it at least once.

 

Get rid of the cats, sure, no problem people do it all the time. The computer stuff can be removed as well. That'll make troubleshooting ALOT easier, when you get in, turn the key and nothing happens you'll know exactly what the problem is.

 

I'm not aware of mileage improvements by removing the computer - fuel injection beat a carb setup hands-down. Now if high-performance is your primary and only goal, the game changes.

The computer gives a lot of diagnostic capabilities. Some problems that it flags, you would be much happier not knowing about but nonetheless, it's doing its job.

If I'm following your train of thought on your recent posts - the EGR system is giving you fits. EGR used to be a nuisance, nowadays, it is an important part of proper all-around engine operation.

Whenever the computer flags a fault, it may have a default strategy in place that allows you to 'limp home'. This may result in operation that is totally acceptable other than the Check Engine light. But keep in mind that the engine is not operating where it was designed.

The benefit of computer diagnosis seems to be offset by the increased complexity. But I suggest that unless you're ready for radical modifications that may not yield results acceptable to your mileage, performance, and budget goals, to keep plugging at what is causing the fault, and correcting it.

 

I have no f'n idea how it would run, that's why I submitted this post. For those of us born before 1970, we can remember simpler engine diagnostic procedures that didn't involve paper clips or watching a blinking light on a scanner! If the gas mileage is already bad, and believe me, it is, then what is the point of all of the computer crap? I had an old 1969 Ford F100 Ranger with a 289 and a 3spd on the column that got about the same mileage and when it broke down, it didn't take a rocket scientist to figure out what broke!

 

Unless you want to switch to a carburated setup there's no way to remove the computer.

The cat's aren't critical to any other systems though, you can hack those right off.

 

Sure - you can rip everything off, including the intake manifold, fuel injection, distributor, and EGR. Go get a carburetor and an intake manifold and a mechanical distributor - along with points and a coil. Have fun getting it calibrated correctly, then tuning it up every 12k miles.

 

If you really want to you could switch to a carb set-up, but EFI is the way to go.


And Yes, you can cut the cats off

 

I'm trying to figure out if your for real on this or not, or are you just stuck that far in the past? I was born in 1970 and I remember that old fashioned stuff, hell I'm rebuilding one right now a '69 Tbird. 429 big block, 4 barrel carb, mechanical fuel pump, and points ignition that puts out 25,000 volts at best. Along with all this I get rough idle in damp weather, I get to work out my right leg every time I start it, and the "pleasure" of doing tune ups every 20-30K. This is why I'm saving up to convert to electronic ignition, and dump the carb for a throttle body injection unit.

Why, you might ask, because it will make the car more reliable and I can spend more time driving it instead of servicing it. If you want to keep the current engine in your truck, complete with the fuel injection the answer is NO you can't dump the electronics. If you want to go back to that old fashioned stuff then yes, you certainly can do it.

 

You couldnt make that work. And good luck with the whole carb thing thats just a pain in the ***. CATs if you dont need em for emmisions get rid of them they suck

 

Yeah, becuase God knows that sure is a pain!

It only makes sure the fuel gets where it needs to go, then makes sure there is a spark. We call that combustion.
Yeah, it was carbed too. You CAN NOT run and EFI truck without a computer. Plain and simple.

 

I gutted my cats on my 95 5.0 and had some serious fuel efficiency increases just clicky on my signature.

 

Alright, so I'm stuck with the EFI and the computer unless I want to completley gut my truck and start over. So, if I cut the cats off, does anyone know what will happen to the sensor readings in the computer? I guess it's going to throw a code, but what, if anything, can I do to bypass it?