o2 issues,help

heres the sich,a few weeks ago i started running lean at half throttle but idling i was running rich as hell ,like burning my eyes.i told all en and he said send a scan .just want too try tooo diagnose my self for now dont want too bother him unless i have too .anywayy when it was doing this every once and awile it would through a po171 po 174 .o2s,i have them disabled for my exhaust .but they are still throwing rear o2 codes ,not sure if this is supposed too happen or not?so this went on for a few weeks.now as of today its still going lean at half pedal ,but now its coding at idle at a red light ,it acts like its loading up but the gauge says lean.all the way.now i think i should get retuned for cold weather ,cause its getting below freezing up here in n.y. at night ,correct me if im wrong.but what im wonderiin is are theyre any other things i should be checking out .tnight im changing a front o2 and plugs ,if theyres any othr sugg. for me too check out wile im in the shop id appreciate it . thanks ahead.

Hmmmm...that is weird...it's throwing a code for something that has been disabled by a tune? You shouldn't have to replace the front ones... A P0171 and P0174 could be a dirty MAF, or a vacuum leak or low fuel pressure, egr valve failure etc---not just the O2 sensors... You might try some contact cleaner of the MAF... Also check to make sure all of the vacuum lines are solid and don't have leaks... Hope that helps...

thats good too know i thought it was just the o2s.ill check all the things u mentioned also.thanks ,what do you think about the tune issue for the cold weather.?

The cold weather shouldn't propose a huge problem...My tune does some weird things in the colder weather... It's a mail order, and it isn't 100% perfect. If I leave it sit for a while, it doesn't want to stay alive at initial start-up. It flutters from 100-1000 RPMs...then I just have to level out the idle with my foot for a few seconds, then the PCM takes over and everything is fine. Lucky enough for me, I am going to go down to H-town and get a live/speed density tune done. It should fix everything...

my idle was doing that today also jumping up and down until i held it up steady too level it out .

Allen did an SD tune on mine and it is so much better than a MAF tune. The MAF tune would die from time to time. It hasn't even thought about dying since the tune update. :rock:

what exactly is a sd tune i know it eliminates the maf but what are the other benifits?and what isnt a benifit.can they be done mail order or actually have to be there ,?

1. SD=Speed Density. Or more commonly known as a "live tune."
2. HUGE benefit over a mail order (MAF) tune
3. And yes, you actually have to be there...

well damn that sucks does anyone know someone in newengland who can do live tunes?

Ya Id Like Tooknow That Too

I live in ct and know of at least 3 places that do live/dyno tunes- Jannetty racing in waterbury, Eastside performance in walingford, and J&M corvette center in manchester. i had my truck dyno tuned at jannetty and love the performance gains.

jes, that must be nice ,theyres only 1 i can find in upstate new york ,and i went too see the guy he does alot of vettes not many trucks ,and the problem is he has another wealthy buissiness and hes real sarcastic ,like i dont care if i do youre truck or not ,boy nelson could make a killing up here the way they treat theyre customers ,theyre great people.let me know if anyone out there knows of any in upstate n.y.

How about TTP and Cartek in the NJ area?

hmm connecticut is like 3-4 hours for me itd prolly be worth it a lil down the road what does a live tune cost anyhow? im thinking Nelson performance should take a road trip to the new england area and inspire a few people around here i hate having no one to race...

ya allen get 1 of those portable dynos and come up here for a big blowout ,youd get alot of people from this site .lol.we have no body that even compares too the king of ls1s .1 week do em day and night get rich .well that probably wouldnt even pay for that portable dyno.did you ever think of 1 of those ?i have a friend that s getting 1 next year and says hes gonna go track to track with it.who knows maybe theyre crap.