Johnny Bliss

I think most of my wierd fuel trim issues has to do with the maf being dirty.i cleaned maf and my ltft is going the other direction with a almost steady -%

Not high but -3.9 highest.

Going to unplug battery and see what it does.

Rear o2 cel came on second start

Johnny Bliss

Need to get a water shield

https://photos.app.goo.gl/kaLjzLjBX4admTVq1

Henry3959

Seriously?
You run your engine with that as a filter?
How about you start by putting some of the trim back in place.

Johnny Bliss

ive had a couple different cone filters on it none made any difference but some did suck water worse

Johnny Bliss

after driving a bunch the LTFT are definitely different without rear o2 plugged in. STFT seem the same. LTFT adjustments are roughly half of what they were with the rear o2 plugged in.

Johnny Bliss

im going to plug the rear o2 back in and reset ecm and see what it does on my way to gym

Johnny Bliss

https://photos.app.goo.gl/XNu7aB6PjbDtAGQC2

Seems clear that the rear o2 has an impact on at least ltft.

Back up to roughly double the adjustment with rear o2 plugged in

Henry3959

Never affected mine at all.
I disabled the rear O2 diagnostics and removed the Post O2.

exninja

iTrader: (1)

What are your two o2 sensors recording?

Henry3959

On my 08, The pre cat O2 is for A/F adjustment
The post cat O2 is for catalyst efficiency
Wide band is just into the down-pipe.

exninja

iTrader: (1)

sorry, i meant johnny.

Johnny Bliss

What do you mean what are they recording?

exninja

iTrader: (1)

What voltage are they reading?

Johnny Bliss

the rear o2 is reading rich and the front o2 moves around a little bit.

at idle the rear occasionally moves around lean around stoich

the primary o2 reads back and forth but rich a lot of the time.

its all kinda a cluster ****. i need to buy hpt but wife doesn't want me to spend money on this car. i might be able to sneak it in sometime.

.7-.9 on the rear o2 while cruising, at idle it settles down .1-.6 mostly towards .6 tho

https://photos.app.goo.gl/h6Ee3RTfBMhUrp362

exninja

iTrader: (1)

one of those is bad. there is no reason that they should be reading differently.

Johnny Bliss

maybe the rear is the bad one cause it doesn't move a lot.

maybe my STFT AND LTFT will be happier with new o2 sensors

exninja

iTrader: (1)

very possible. then you might actually get the cat code. it would explain why you haven't been getting it till now.

Johnny Bliss

ill buy a couple not sure if i can put them in today. the front and rear should be the same part right?

exninja

iTrader: (1)

no, likely one is heated and the other isn't (not that it matters much w/o a cat). The pigtails would also be different.

there might be a way to figure out which one is bad, but i can't think of it. I'd guess the secondary is bad since it's throwing off the LTFT.

Johnny Bliss

ah yeah you're right i forgot about the connectors.

Henry3959

So how did the 2 new O2 sensors help your catless LTFT's?
Trying to diagnose a post O2 without a cat is like trying to diagnose a no start without a starter.

Johnny Bliss

I haven't gotten them yet I might tomorrow. Been really busy.

I dunno if it will help or not but these o2 both have 110k on them

Johnny Bliss

the car seems to idle smoother, and part throttle seems smoother. i'm getting less of a exhaust smell. but i will give it some time to know for sure.

https://photos.app.goo.gl/zgxycf3rUuaeYuB33