any thoughts on data

[nickhinton]

hi guys, I'm new to the "tuning" world and looking at a live data for my car. Ive done a lot with obd2 stuff but finally got my car hooked up today to see what it was doing. What im having an issue with is the car acting funny when it warms up and goes into closed loop. When the car is cold in open loop it feels totally different than when its warm. I have a wideband which shows a typical reading from 10.8-12.1 afr when cold in open loop and when i hot closed loop at idle i lean out to 14.7-15.5 afr. I have no vacuum leaks, and the 02 values on the scanner (bank 1 and 2) kept fluctuating from about 18mv to 900mv repeatedly while blm started at 128 on both banks and pregressively dropped to 108 on both banks. My question is will running the car with headers a catback k&n intake, free mods 160 thermostat and emissions/air pump delete without a tune cause the car to act like this or are the readings normal? im not fimiliar with what the data should look like so any input would be helpful thanks for any help guys

[1BADAIR]

afr is normal. block learn is off some due to mods some so tweaking could help though

[hoogiesngrinderz]

Have you changed injectors? BLM dropping to 108, which is the minimum limit, means it's pulling fuel (leaning out) to try to maintain stoich (14.7:1)

[nickhinton]

Still have stock injectors in it, just replaced the maf and tps car runs good still but I just couldn't figure out why the drastic change in closed loop. How much do you really benefit or gain rather from a tune on these motors? Thinking that should be next on the list

[JoeliusZ28]

Sounds to me like you have 1 or more bad oxygen sensors. Those free mods shouldnt mess with anything.

[meissen]

160 thermostat usually requires a tune. I would recommend getting new o2s in there to make sure your o2 readings are correct. 10-12AFR is really fat, IMHO.

[nickhinton]

hmm, i just put these sensors in about 50 miles ago. that being said they're bosh sensors from autozone. Maybe ill try some delco ones and see if i get any change, or are there any other brands you guys suggest? I've seen to stay away from Bosch but I got a good discount on them from working there, but if the Delco's are really more accurate ill go pick some up

[JoeliusZ28]

I'd be willing to bet thats your problem. I had a bosch sensor give me fits back in the day. after that, O2 sensors are delco only parts IMO.

[hoogiesngrinderz]

Seems to be hit or miss with Bosch, but I doubt Bosch o2's would cause your car to swing full lean.

Personally, I'd put in a new set of injectors. It isn't often that I see BLM's drop to 108...makes me think an injector is leaking/stuck open.

[nickhinton]

alright that settles that, buying some Delcos next week when i get paid. As far as the injectors go seeing as i don't have an injector balance tester do you think the old pop the rail from the intake, pressurize it and see if any of them drip would suffice? I know injectors aren't cheap.I did ohm them out today and all were within 10% of one another with an average of about 13 ohms (12.9-13.2) were the readings

[hoogiesngrinderz]

About my previous post, I meant rich...not full lean.

As long as you have the injector clips to hold them in the rail, I see no problem with that. If not, I haven't had an injector pop out of the rail on me but it is possible, and that would suck There should be a jumper connector that you can supply 12v to run the pump while working in the engine bay. I keep a hand held momentary switch in the garage for such occasions.

It's definitely a test I would do before buying new or rebuilt injectors.

[nickhinton]

well now im kind of at a loss here, changed out the fuel filter today since it had ever been done since i owned the car, pulled injectors and pressurized the rail (help pressure at ~42 pounds koeo) and none of the injectors were leaking. I swaped my 180 degree thermostat back in i hopes that it may help cure the problems. The car seems better after the new filter injector o rings and thermostat but im still getting a lag off the line. after im in closed loop and go to stab the throttle at idle it feels like the car hits a brick wall and wont hardly move until i hit about 3k rpm and it takes off like a bat out of hell and pulls through all the gears. It seems like now my only problem is the off idle stumbling. Thinking maybe the 02 sensors are just to slow to respond