:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: random-strike on May 28, 2014, 11:08:08 PM

Title: downstream o2 sensors
Post by: random-strike on May 28, 2014, 11:08:08 PM
should they bounce around or stay steady?
Title: Re: downstream o2 sensors
Post by: highroller54 on May 29, 2014, 09:38:26 AM
They don't stay steady but shouldn't switch as fast as a primary o2 because of the cat. If the cat is fucked it will react quicker. They will still read/switch from full rich to full lean though.
Title: Re: downstream o2 sensors
Post by: random-strike on May 29, 2014, 11:19:04 AM
I have oene that stays steady sometimes and one that bounces.

I wonder how you tell if its the cat or o2.

no engine codes
Title: Re: downstream o2 sensors
Post by: highroller54 on May 29, 2014, 03:11:24 PM
Hemi jeep iirc?
If its running like shit it can/will be all over.
Tell me what year/model/engine and exactly what it runs like, not what you think the problem is.
Title: Re: downstream o2 sensors
Post by: random-strike on May 29, 2014, 04:32:08 PM
Hemi jeep iirc?
If its running like shit it can/will be all over.
Tell me what year/model/engine and exactly what it runs like, not what you think the problem is.

05 jeep hemi yes

hesitation accelerating especially in 1st gear from a stop, kinda lurching. hesitates while cruising a lot. like a misfire. idle is rough, but not super rough, but doesn't idle as smooth as it should.
runs smooth in open loop when there was a cel on. I put new primary o2 sensors in, without the cel on it runs like it did before the CEL, hesitation studdering etc...

when its cold, first start in the morning, it runs smooth for a few miles i'm assuming its in open loop.

I thought secondary o2 sensors wouldn't change how the engines runs like just monitor the cat converters???

this is one bank

1x1
(https://scontent-b-sea.xx.fbcdn.net/hphotos-xpf1/t31.0-8/10329824_745719452117227_8719366996765523313_o.jpg)

1x2 it was bouncing for a while then after driving about .5 miles it started doing this
(https://scontent-b-sea.xx.fbcdn.net/hphotos-xpf1/t31.0-8/10259098_745719448783894_8045029717027251970_o.jpg)
Title: Re: downstream o2 sensors
Post by: random-strike on May 29, 2014, 04:33:43 PM
the other bank, the 2x1 o2 sensor bounces like normal, like the 1x1

but the 2x2 is bouncing all the time back and forth. I don't have a graph of it right now
Title: Re: downstream o2 sensors
Post by: highroller54 on May 29, 2014, 09:47:11 PM
Fucking crazy stupid busy today, I didn't have any time to do shit. So did it ever get a check engine light? Or just started running shitty so you put some o2's in and a tune up but it didn't change anything?
Title: Re: downstream o2 sensors
Post by: highroller54 on May 29, 2014, 10:06:03 PM
Also What do you have for diagnostic equipment?
Title: Re: downstream o2 sensors
Post by: random-strike on May 30, 2014, 12:18:47 AM
using torque pro

i put egr, pcv, plugs, wires. i just put the secondary o2s in and it seems to run better on first drive. got the lurching out of its when accelerating. i'm pretty hopeful this will solve it. need to drive it a bit more.

its never thrown a cel, the only reason i got a cel before was because i cut the o2 wires so it would run decent until i changed them :)

normally the secondary o2s shouldn't make it run weird but apparently some cars it does
Title: Re: downstream o2 sensors
Post by: highroller54 on May 30, 2014, 10:01:05 AM
I have had secondary 02 sensors make the odd unit run like shit. I don't know why as they are just cat monitors but I have. I can't think of what brand they were that had done it to me or the specifics but I've seen it.
Title: Re: downstream o2 sensors
Post by: Burntrubber87 on June 17, 2014, 04:32:31 AM
Sounds like you've got it pinned down, but all of those symptons fit the bill of a converter clutch thats locking when it shouldn't..which is a common chrysler thing..if you're not auto then i would scope the MAF and or map whatever ya got.