I'm looking for some advice with my 300 I6 in my Bronco, mostly MPG and performance ideas. I know this has been asked many times. I usually tow with my Bronco and use it as my daily driver.

Do they make performance modules for 300 I6 EFI engines for Broncos?

I have installed a exhaust system but I do not have a cat on it. My check engine light in on due to me unplugging my EGR sensor plug because it would spit and spudder occasionally while I was driving and seem to not have no power. Found a wire that was broken and it look like it ran to my cat but my cat was damaged and I removed it. Now I have an exhaust leak on my Air Injection Reactor pipe (the rear little pipe that inserts to the head)...we have welded it but it is broken again. I am thinking about removing it but the thing is so rusted.

 

The air injection that is missing due to the broken pipe is most likely causing your performance issues. Loss of air injection causes the engine to run rich so the computer compensates by dialing the air/fuel mixture way down so its extraordinarily lean. This fouls plugs and causes terrible throttle response problems. My suggestion is to fix the air injection and clear any Codes before moving into the realm of performance mods.

As to those performance mods, keep in mind that the 300 is a workhorse. "Poor man's diesel" is probably the most accurate description I've ever heard for it. Typical minor mods like CAI's, better flowing exhaust work well. If you want to get into computer tweaks and the like, check with the folks in the FordSix forums. There is NOTHING they don't know about the Ford I6 mills.

 

I was thinking about ditching the AIR pipe since I don't have a cat but I guess it still operates through my exhaust pipe?


Are performance modules worth getting?

 

Where exactly is the break in the air injection pipe? If its broken at the cat. end and there is no cat. then there would be no exhaust leak. If its broken at the diverter an the check valve is not broken, there still is still no exhaust leak. If its still attached to the cat AND the check valve is broken or its rusted below the check valve then you have exhaust leaks.

If the pipe we are discussing is actually the EGR return pipe, then you will still need to replace the pipe. The EGR is something the computer is "expecting" to see based on the programming of the computer. There is no way around a broken EGR pipe short of fixing it properly.

 

It runs where the manifold is on the inside. 6 little tubes run into the head then runs to a tube which I think runs to the smog pump...it's broken on the last one near the firewall...

 

Ok, so its one of the steel injection lines into the head. If you intend to keep the EFI and EEC-IV computer, I would strongly suggest keeping the air injection because the injection just downstream of the exhaust valves DOES affect your O2 sensor readings. Thing will cause the computer to constantly compensate for the lack of fresh air in the exhaust. This runs the fuel/air mixture VERY lean to compensate. (Not to mention the obvious exhaust leak.)

I don't think I need to explain what happens when you run very lean for extended periods of time. I'm looking at doing the same replacement on the 300 that I'm putting into my 93 because I have a couple of cracked fittings into the head. The price tag for the entire manifold isn't the least expensive thing to replace but the RockAuto number hovers around the $65.00 mark for the entire manifold. Really a small price to pay in lieu of repeated fouled plugs, overheated cylinder walls and valves, and loss of performance through a perpetually lean condition.

While the manifold can be removed and the injection ports plugged permanently, there is no way to effectively fool the computer to keep the situation I delineated above from becoming the issue without removing the EEC-IV system entirely and going backwards to a carb or some other induction/fuel deliver system.

 

How can I get my Check Engine like off since I have my EGR sensor plugin unplugged? Someone said I can block the line or something to fool it..?

I guess I can take off the manifold that covers the pipe, try to remove the pipe and weld it or get a new one...

 

Well, with the EGR disconnected, the system is triggering multiple fault Codes from EVP sensor failure to false or erratic O2 sensor readings. To simply block something off won't fool the EEC-IV system into believing everything is fine. One disconnected component affects at least two or three others in a chain-reaction. That is why in all of my posts I ALWAYS recommend just fixing the problem rather than trying to bypass it. The system is more complex and more integrated than most folks are willing to admit much less be able to figure out how to "fool" it. I've never tried to "fool" it so I can't help you there. Sorry to have to be your "Snoopy" on this one.

 

I appreciate the help. Well there is a broken wire off the EGR plug and I don't know where it goes but like when I said before that when I plug it up..it spits and spudders and won't go but then after sometime the power comes back but still spits and spudders until I unplug it from the EGR..

 

sounds more like you got some maintenance to do before worrying about modifying. I'm with greystreak in that the best, and the most beneficial thing you could do right now is to fix the AIR and EGR systems.

for the pipe: if you go to a junk yard you will need lots of PB blaster, patience, and luck. and you would still need to clean it out, but you might want to check ebay for a new one.

as for the egr, if you have a manual (if not, it should be at the top of your list. get a good one!) it should have the wiring diagrams to help you figure out where the broken wire goes, connectors can be found by any decent parts store, or you can go to a yard and find a good one, then cut it with however much of the wiring you need. also pull the actual egr valve off and look at how dirty the internals are. there is a good chance that it is sticking. it can be cleaned, but you would be better off with a new valve.

as far as "performance modules" go. I wouldn't spend a dime on one. if you need to go farther than what the factory computer can do, which is quite a bit, you will either need to step up to tweecer (or the other that i can't remember the name of) to reflash the computer, or go to an aftermarket computer such as a fast, megasquirt, xfi, etc.

 

Well I stopped the leak..crimped the tube and plugged the broken one..it whistles..

I've found that the pipe that the air pump inserts air into the CAT is broken AND I did mention I do not have a CAT no more so basically its pumpin air to nothing..

I don't know whether to buy a new tube or not now...

 

Hey Grey, you think I still need to get the AIR tube even though I don't have a cat?