jeeptester

I have a LY2 2008 4.8 in a TJ Jeep.
The harness has been modified and the ecu vats removed. It seems to run fine. It had several O2 issues at the fire up but it didnt seem to affect the running so I just ignored it for a while and drove it. I have the Jeep down for a rear axle swap and thought this would be a good time to try once again to fix these nagging issues with the harness.
I have checked each wire going to the o2 for breaks and shorts, and also swapped the sensors and the error stays on the same sides unchanged after clearing,

Codes are
P0030 BANK 1 SENSOR 1 HEATER CONTROL
P0053 BANK 1 SENSOR 1 HEATER RESISTANCE
PO054 BANK 1 SENSOR 2 HEATER RESISTANCE
P0135 BANK 1 SENSOR 1 O2 SENSOR HEATER
P0134 BANK 1 SENSOR 1 NO ACTIVITY (ONLY SOMETIMES SHOWS UP)


Questions
1. Are the errors causing a decrease in performance and MPG?

2. Who do you guys recommend that I could check?

3. Who do you recommend me to send the harness and ecu to?

Thanks
Lowell

jeeptester

???

I know its a long shot but IDK what else to try so Im ordering two DENSO O2 sensors today if thats not it, I guess Ill have spares.



Lowell

Bowtie316

iTrader: (1)

Yes, i would think it could cause a decrease in performance and economy.

I would start with finding the pins at the pcm for each of the wires going to the bank 1 o2 sensor, and ohm them out. visually checking them won't work, the wire can be broken inside the insulation.

Who built your wire harness?

jeeptester

S & S PERFORMANCE in Ark , modified the truck harness

He says he checked them when I sent the harness back three times trying to get it to start. THen figured out it was (pin 53 remote start) had to be grounded at that point I was just glad to get it to run lol but now Im going to figure this out. I ordered two O2 's from rockauto this morning, I really think thats a waste but worth a shot I guess ,

I have got good at pulling that harness off

Bowtie316

iTrader: (1)

IF everything ohms out okay (I wouldn't take S&S word for it) then I would have to assume that you have a bad ground or there is a problem in the PCM. Especially since you said you swapped sides and the codes poped back up on same side.

Have you done any scanning to see what the o2 sensors actually read?

jeeptester

The only scan info is the codes listed, my scanner does do live data but I dont think it does for the o2 readings

I was also thinking ecu, but Im told they just dont go bad often and if they did it would be more of a blown or go kinda thing and not so specific a failure, IDK

I ll post results of o2's when they get here.

The picture below is what I should ck to be correct?
And pin 12, 57 and 56 are the pins for bank 1 sen1 Is the pin 12 the heater ground provided by ecu , 57 sensor and 56 ground ???
and Bank 1 sens 2 is 65, 10 ,and 11



http://www.lt1swap.com/pictures/Engi...20-%20HO2S.gif

jeeptester

.

The local dealer said they might be failing after warming up so against my better judgement I replaced both O2 and yep no difference .

I'll be tracing wires today, (again)

Here are some live data I have no idea what some of this means. the cat temps I assume are actually o2 temp?? as there are no cats

This reading was after a short drive, the cat temps at speed were about 3x this

jeeptester

This code will pop up immediately after clearing

jeeptester

jeeptester

oh forgot to mention the harness guy said he deleted the rear o2's

jeeptester

I traced each wire and here is what I found using a cut off end of a o2 sen , a small battery and test light.

I cant seem to find the correct pin out of the 2 big plugs that go to the ecu for MY engine. The ones I have would indicate the wires are WAY off . (hard to believe they are ALL off but possible I guess)

This is what they are

Sen 1 Bank 1

Tan "A" on sensor to pin 36 in X2 plug
Pur/Wht "B" on sensor to pin 37 in X2 plug
Grn/Wht "C" on sensor to pin 72 in X2 plug
D pink 12v +

Sen 2 Bank 1

My doc says these should ALL be in X1 plug but they are in X2 IDK if thats correct.

Tan "A" on sensor to pin 40 in X2 plug
Purp "B" on sensor to pn 39 in X2 plug
LightGreen "C" on sensor to pin 73 in X2 Plug
D pink 12v+

LS1MCSS

iTrader: (18)

Sign up at ALLDataDIY so you can get the correct schematics for your engine. It will cost you around $40 a year but you can print any schematic needed for your engine. Make sure the vehicle you register is the same type the motor is out of. That way you know you have the correct schematic for the O2's.

Bilster

iTrader: (21)

Is you harness built by Sand and Street Performance out of Arizona? Also known as S&S Performance? Have you tried to get tech support from them?