8 miles to the gallon, any ideas?

e-brake on? trailer?

just ignore that, I'm in one of those moods.....

more seriously I'd think a blown cat would only kill mpg if it's clogged. Is the ecu OK?
Can you get an AFR on your fancy scanner? that'd tell you whether the EFI knows you're running rich if nothing else; running that rich it's almost surprising you're not having flooding issues or breathing fire out the tailpipe.

also, wouldn't running so rich kill your hp? that might lead to a heavier foot trying to get back to a normal feel which would in turn suck even more gas.

 

oh yah a blown catalytic converter would definitly kill your mpg

 

that is something i have noticed, i have absolutely no power, i can put my 4wheeler in the bed and have to slow down and go into 3rd to get up hills. and yes while i may not drive fast i do probably have to push the peddle a little harder than i like to get it to do anything. also i think not only is the cat causing me to run to rich i also think the broken honeycomb is causeing alot of restriction in the exhaust, because the other day i went around a corner and all of the sudden had power, and then i wnet around a corner the other direction it lost the power. this weekend im going to take off the cat and dump out all that loose honeycomb... see if that helps

 

im sure that comment made him happy, gold star to you sir. extra points for the list of mods on your mustang. sorry

thats no good... have you taken your intake off and had someone push the throttle down and seen if the throttle body opens all the way? do you have bolt on or weld on cats? if bolt on take it off and see how she responds. does she idle at a high rpm? that would or could indicate a excess of fuel in the cylinder. easy fix is you could reset the ecu by taking the positive cable of the battery and after that turning the lights on you truck on, then rehook the cable and it should reset it. might blow a fuse, but chris4x4 helped me with bad gas milage in my 06 last year, and this and above helped restore my gas milage.

ps while your looking at your throttle body make sure you clean it too you clean rags and try to catch all the debris that comes loose.

hope this helps

 

already checked my throttle body, wasn't able to get CAT off this weekend but going to tryy something my neihbor suggested, instead of spending hours trying to remove the CAT imma just cut it open, dump it, and weld it back together. and im not sure, bolt on i think, it's factory

 

Sounds Like a stuck injector to me. Hollow out the cat also. use a good penatrant spray on the bolts a few days before you take it off.

 

now im throwing a code for my egr circut

 

and now my speedometer gear went out...

 

Might be your ecu also. Have you ever gotten it wet. Bad ecu could cause rich condition, speedo being out, and throw a code for the egr circut. Pick one up at the junk and see if that fixes it.

 

Either the neighbor is siphoning gas at night or you have major issues. Pull the codes yet? Stuck injector would make a high idle, unhook the battery for 4 hrs and then drive it? Does it drive normal?

Might be time for Stealership? Could be the best 75 bucks you spend.

 

Stuck injector with a clogged cat might not idle high.

 

no high idle, i think my ECU's good, and my speedo is a definate mechanically controlled one, not electronic. so the speedo cables's fine, just the gear, also my vaccume is fine, i brought it into the auto shop at school and the teacher (a master tech for toyota/ honda) said it's perfect. the egr valve works fine too... if u induce a vaccume in it the engine shuts off, just like it's sopposed to. and now every time i hit a large bump big clouds of white smoke (looks like steam) come out from under the hood, and no it's not overheating.

 

.... and the neghbor drives a cummins... no gass stealing from him

 

Any smells associated with that event? Steam like that might be from some kind of watery fluid splashing onto the headers. If it smells kinda sweet it could be coolant (I've always thought that boiling radiator fluid kinda smells like maple syrup) coming out of a cracked or uncapped reservoir. Not sure what color brake/power steering fluid would make.

Any chance you lost a bolt somewhere and part of the header is loose on the engine? If that's flapping open on bumps you'd def get some smoke as well.

 

Also, have you checked your engine compression?

 

If you want to pm me your number I could probably be of more help.

 

Hey have you pm chris4x4? he knows a shitload about the tacoma's he might be able to help. But then again i am sure he has seen this post and would have chimmed in if he knew. But its worth a shot.

 

no smell associated with the steam under the hood... no loose bolts, no leaks... this truck just confuses me. and sorry can't pm my number (no house phone and i have a prepaid cell with only minimal minutes) everything other thatn the engine on the truck is rock solid and completely reliable, i think i just got a lemon engine. im getting new tires soon and they'll be 32s instead of the 29s that are on it... who knows, maybe it'll help

 

No that would make it worse.....bigger tires=worse gas mileage

 

Yeah you deffinetly have to get the problem fixed before you go get bigger tires my dude