As seen in my other thread about my diff, you may know i got that fixed and headed to work. Ran just like it normally would. before i continue lets preface this by saying the exhaust is nothing but a straight pipe after the stock manifold. It runs to a flowmaster super series(?) Heres the kicker, no 02 sensors at all, Upstream and downstream are gone. So like any car without 02 sensors it gets to temp and does not like partial throttle at all, lacks power, and guzzles fuel faster than a teen getting a slushie from 7/11. driving wasnt to bad, with OD on when it would shift to a higher gear cruising it would buck pretty bad at partial throttle. And obviously going up hill it would hold its speed well and maybe slow down by a mile or two. Tonight was different, i started up my truck, and i noticed i consumed a bunch of fuel, already which couls either be a problem with the truck or i didnt see how much i used. I headed to the gas station around the corner and it sounded like there was some rattling coming from my exhaust. (might have an exhaust leak from the left header bc i tried undoing the bolts to take the exhaust off and only got one bolt slightly undone before the bolt started spining bc no wrench on it) nowlets grab all this jumble of info into a story. (Im very tired so i apologize for the jumble of info) ANYWAYS. I went to leave work, stopped because of the rattle, found nothing and left for the gas station. I had to wait for my gpa so i kinda drove around the corner and had the truck on and off a few times. Got gas then went to head for home, but then i noticed a few random missfires leaving town. got onto a back road and noticed that i barley had any power, like at all. Any hills (even slight ones) i could be at full throttle and it would only be at like 2K not wanting to downshift to give me power.(OD is off as it makes the truck run smoother, and yes ik its meant to help with mpgs and such) i stopped in the road and was gonna floor it to see if i couldnt clear whatever was in the system out.. Welp second i mashed the gas it stalled, tried again and same thing. so i very gently eased onto the throttle and it chugged along and finally got to speed. Went to hop onto the highway and got stopped in the middle of the road because it started off sputtered backfired and died. I almost didnt make it up the hill because i was full throttle and my speed was dropping fast. I was at a crawl when i got to my house. I dont know what could be going on all of a sudden.its like its in a type of limp mode.. Mind you it misfired and backfire the whole way home very randomly

 

This all sounds like a bad cat... But it could be TPS, to Rich or lean, or dirty throttle body

 

I dont have a cat😂 like i said straight pipe to a flowmaster muffler and no 02 sensors. TPS? Isnt that throttle position sensor? Ill look into it but im really not looking forward to tearing my truck apart again lol

 

I would start with a compression test and see if you have bad/burnt valves.

 

Your truck only had one O2 sensor, which you really need......

I am sure the truck is setting codes for the missing O2, getting any others?

 

Are you aware of the the plenum gasket issue? Misfires and backfire are text book issue of it. I would at least put the upstream 02 back on because the pcm has no idea of what the engine is doing. You can get a 02 bung drill out a hole in the exhaust then weld it on.
http://www.hughesengines.com/Index/p...p?partid=27091

 

Wasnt aware it only had one, but yes throws a code for battery disconnect (had battery unhooked a short while ago) 02 sensor, injector # control circuit (flashes 27 code twice, dont know if that means anything at all) ive been trying to find a place to install my 02 sensor, VIP doesnt take customer parts apparently so ive been looking for other places. I think i have an exhaust leak at the header down pipe, i tried unbolting it but only got it undone the slightest bit (less than a full turn before the bolt started spining because i had no wrench)

 

Seeing code 27 twice, likely means you have two injectors malfunctioning. (or their control circuits.....)

Try a power balance test. Warm the engine up to operating temp, and disconnect the IAC on the back of the throttle body. Then, disconnect injectors one at a time. you should see a significant change in rpm as you unplug it, if you don't, that's one of your problem cylinders.

 

Drove the truck a little bit to get it to temp, took off the IAC at the back of the throttle body and disconnected the injectors one by one. Injectors 8,4,2,1 had no change in RPM while the others affected the RPM and even caused some more of the backfiring. I know this probably sounds dumb but a lot of people ive mentioned it to in person say it could be a clogged fuel filter.

 

I highly doubt that and even so the filter is in the tank...