94lt1m6

iTrader: (9)

So...while i was waxing a mustang today, my car misfired 3 times. Then shortly after the SES light came on. So i went and got it scaned. The scan said it was running lean on both sides, and showed a problem with both the o2 sensors, and said it had multiple random cyclinder misfires. Now if you read my sig of mods, it has no o2 sensors. And im guessing it says its lean cuz of the mods, and needs tunned? Is'nt there a way to up the fuel pressure a little bit to maybe help that out? And does anyone have any suggestions on the misfires?

Michael02hawk

iTrader: (26)

This is your 1st problem.

I'd start by fixing that, then yes, have it properly tuned.

94lt1m6

iTrader: (9)

Well...its got LT's on it, and true duals. No spots for o2's and it hasen't had a problem for 300 miles untill now. Can't i get the o2's tuned out when i get it tuned?

boondiggys

iTrader: (165)

you need o2 sensors for the computer to run in open loop mode...

94lt1m6

iTrader: (9)

So what am i supposed to do, i can't find the wiring for the o2's, and then i need to drill holes in the headers and put o2's in them. Also how come it ran fine for the last week and then all of the sudden its missing a mandatory part?

1987firechicken

Your car will run without them but horribly your computer measures AF ratios with them. Your LT should have come with O2 bungs welded in them get a shop to do it but you DO NEED THEM!! Something is gonna go wrong without them and your probably dropping horsepower to boot. I would do this ASAP. As far as the wires you should have them up by the tranny under the K member (least they were in my car but it is an LS1). That is why tuners have wideband O2's they hook up to your exhaust and others put them in to monitor AF ratio. Also do the basic check on your plugs and replace wires to be sure they arn't bad. Good luck and get those O2's back in stat!!!

94lt1m6

iTrader: (9)

I guess i don't understand why i cant just have it tuned out. Also the car doesnt have cats. Its just Header 3 ft of 3" pipe and mufflers. I will look up on the k member, but if i dont find them, than what am i to do?

94lt1m6

iTrader: (9)

I also found a few 'misplaced' wires. I found a Red and Black wire leading into a blue male conecter that is ran under my intake lid, and hanging infrount of the radiator. It is also acompanied by a small vacume line. They are wraped together in those plastic wire protecters. That come out of a Large group of wires that run across the frount of the engine.

Sideways240sx

iTrader: (22)

The blue male connector might be for the iat on the intake.. Is there no sensor? and connector just sitting there. As for small vacum line i dont know. Need a pic.

Does your car have no rear 02's? the car factory has 4 02 sensor.. 2 front's 2 rears. The rears can be deleted, but the fronts you need to keep. They constantly monitor your a/f ratio, and without them the computer doesn't know how the engine is running, and to add fuel or take fuel away.



ps.. I jut looked at your sig. I see you have pacesetter headers. The race header, or the egr headers all have the bungs for the front 02's. If you dont have them in, you have a huge leak. You will need extension's for the 02's or get the corvette rear 02's, part number is 13111 i believe. They will fit in, and have longer wires so no need for extensions. They also are believed to have a better heater.. I bet you have the front 02's in, and you just dont have the rear 02's..

Get under there and figure out whats going on.

Chris

1987firechicken

You will not want to tune out your front O2's they update your pcm with the AF readings from your exhaust, your thinking of the rear O2's that just tell you if the cat is working which you DO want to tune out. I'm not sure why the O2's are missing anyhow. Right now you pcm is seeing the air coming into your engine but has no clue how well it is burning in the cyliders which is NOT GOOD. You may have O2 sims on the front which is gonna cause issues. You want to put some O2's in bc if your running lean your gonna end up with a nice hole in your piston and a little less cylider wall and you wouldn't even know it bc you pcm can't read the ratios. Like I said before most guys put MORE O2's in there car to keep it running in top shape not take them out. As far as the wires I'm not sure I'll take a look tommorow at mine to see if I have some of them up there but I haven't noticed anything. Just curious but did you buy the car like this or did you do the mods?

94lt1m6

iTrader: (9)

Ok...There is no leak, so i know there is not a hole. I will jack the car up and look. I know there is no rear at all. The car has never been jacked up, so i didnt want to mess up the pretty little frame with no jack marks on it, but i guess i will to figure it out for sure. I looked all over and didn't see any o2's but i may just not be able to see them from the angles i am looking at. I'll take a pic of the wires ASAP, i did notice that there is a hole that has been blocked with tape on the DS intake. Maybe thats were it goes?

94lt1m6

iTrader: (9)

Oh yea, I bought the car like this. The guy that i bought it from is a halfasser i have found that out since i bought the car. Its nice, but all the mods are half assed.

1987firechicken

The hole that is blocked on the intake is the air hose that was going into the pump more then likely. Do you have a rubber hose running the length of the driverside fender that goes by the brake booster? If not the AIR pump was removed and that may explain your loose wires. You shouldn't have to jack on your car to see the O2's they should be visible with the pacesetter's the O2 bungs are on the inside of the collectors and can be easily seen just by getting at ground level. The ONLY way you should have no front O2's is if your running a speed density tune but you more then likely are not bc it is normally only done on all out drag cars or crazy powerfull street cars.

94lt1m6

iTrader: (9)

Well...the check engine light is off now for the time being. Don't know why it comes and goes. I still haven't found any o2's but i may just not see them. So lets assum there are o2's. Now what about the random multiple cylinder missfire? And is'nt there a way to turn up the fuel pressure a couple psi for a few more HP?