1hander

when i bought this car, i removed extra cables that i know for a fact belonged to 02 sensors..and a couple of other cables that looked like they belonged to a tuner...

it has headers, x pipe /no cats, exhaust looks to be 2 7/8 all the way way... there are two O2 sensors in the x pipe.. but it looks like the front O2 sensors are deleted... the connectors are there but no sensors..

when i look at live data... with the tech2... im looking at the feed for sensors 1 and 2 ..........bank 1 and 2 ... now if im not mistaken i should not be getting a reading on bnk 1 O2s.... can someone tell me whats going on here...im getting a signal at all for O2s

also i noticed that the AFR is at a super steady 14.7... and i know theres no way the afr can be locked in like that... if i hit the accelerator it does not change... stays locked at 14.7... almost like its being forced to stay in open loop mode...

maybe someone can explain to me if these are some common practices... im pretty sure its running rich as hell cuz maybe a cam was removed..or larger injector were left in place after removal of other mods,,,im not sure where the afr should be for NA .. but i tuned my turbo cars to 11.75 all the way to 36 psi with no problems other than taking out a bit of timing in a few spots in the rpm range.but this thing is so rich that if i nail it in forth for about 4 seconds and come to a complete stop theres rolling clouds of rich smoke coming from the tips... the smell inside is too much.. im not a ******...but its too much for even me..

the slip joints are all leaking so im welding in vbands all the way back

also...if the previous owner used his own tuner ...do i have to use the same thing he used.. is there any way i vcan find out if hp tuner will work before i buy it...( for example...if the previous owner used something other than hp tuner ..will hp tuner still work over it)

just looking for some insight... also is there a chance that the previous locked me out of the ecu... and how would i find this out.. im taking it to a shop next week to get looked at... and see about a tune... but at 450.00 for just a bit more.. i can get hptuner do it myself..

schpenxel

You'll get a ~450mv "reading" if no O2 sensors are there. What are you seeing?

14.7 is the commanded AFR; it can't read the actual. Even if it had front O2 sensors they can't actually read AFR, they can only tell if it's richer than 14.7 or leaner than 14.7 (or, more precisely, richer/leaner than lambda=1 for whatever fuel you're running). That's the crappy part about GM using narrowband O2 sensors.

HPTuners can read the tune regardless of what was used before IF it isn't locked

Anyone can read it for free with HPTuners. If they can read it, it isn't locked. If they can't, it probably is

1hander

hey ... thanks for the response,,,, you are correct they are 450mv... i didnt know a vacant O2 would do that.. ive never come across that before.

based on what your telling me.. everythinng is ok.. other than its running really rich.. im sure missing cats have alot to do with the raw fuel stink... im going to wait to retune till i get a cam, intake manifold, CAI.. ... ill be be hashing over getting that retune or getting HPtuner .. i just wish there was a way to make sure the ecm isnt locked by a previous tuner..

again thanks for the info..

schpenxel

I wouldn't really call running without O2 sensors "OK" honestly. I'd put them back in once you have HPTuners

1hander

its the exhaust smell... i cant stand it... maybe i am a ******..LOL... the plan is to put vbands on all the joints of the exhaust, add in some cats, put the o2s back in.. install mods i purchased...,,then start playing with hptuners.

im not worried about the little bit of power loss that cats will cause..but since it has longtubes on it im worried the cats may not get hot enough to work..

do you by chance know if all four O2 sensors are the same, as in have the same connectors ... i want to go ahead and buy the missing ones but im not sure if its the front or rears that are missing... am i correct in assuming that the fronts are the ones that the ecm is using to run things and the rears are the ones missing... (and the fronts just have an extenson on them..) i can make sure with the tech 2 i think.

is it the same as other cars ive had... bank 1s are pre cat and bank 2s are post cat

schpenxel

No, they're different connectors. The fronts have a triangle'ish black connector, the rear ones have a square connector.. the rear ones you can leave out, no use for those

Cats cost so little HP these days that it's crazy to not run them.. I've tried going without them and it's just miserable for me so I know what you mean

Front connectors look like this:




Rear look more like this:

1hander

thanks... when i was playing with the tech 2 .. the car had been sitting at idle for 15 minutes or more... i was looking at the open loop closed loop test... where you can toggle between open and closed loop... and it was always in open loop...so i could toggle to closed loop ..(i would hear a bit of rpm chnge) then when i moved out of that test it would go back to open loop... so i think somebody screwed with it and turned something off with a tuner...

either that or it just wasnt going into closed loop for some other reason..

schpenxel

If it doesn't have front O2 sensors then it can't really be in closed loop

1hander

ill check to see which ones are missing