Disco ii riddled with codes
Disco ii riddled with codes
Hi All,
have a 2004 with three main fault codes.
O2 sensor 1 bank 2. I replaced the O2 to no avail.??
The next one is: Fuel mixture imbalance, which I am A$$uming has to do with the O2 sensor.??
The third code is: 4th gear incorrect ratio, which ( using the SWAG principle) is due to a faulty transmission speed sensor. I also know that it’s possible to get a faulty (new) O2 sensor so I ordered another one. Any suggestions or comments would be greatly appreciated. Thanks
have a 2004 with three main fault codes.
O2 sensor 1 bank 2. I replaced the O2 to no avail.??
The next one is: Fuel mixture imbalance, which I am A$$uming has to do with the O2 sensor.??
The third code is: 4th gear incorrect ratio, which ( using the SWAG principle) is due to a faulty transmission speed sensor. I also know that it’s possible to get a faulty (new) O2 sensor so I ordered another one. Any suggestions or comments would be greatly appreciated. Thanks
Best practice when you have a one bad 02 is to swap left and right, that way you can confirm bad sensor vs bad wiring or bad something else.
Bad speed sensor does not just give fault in fourth, it gives fault for all the gears. Incorrect ratio is typically a sign of clutch slippage, how many miles on the truck? ZF HP24 not known to have 4th gear issues, would be unusual. Code occurs when output shaft speed does not match expected output based on gear selected and engine rpm. My guess is maybe front clutch is slipping but manifest as a 4th gear issue. Recommend you get a complete trans from a breaker.
Bad speed sensor does not just give fault in fourth, it gives fault for all the gears. Incorrect ratio is typically a sign of clutch slippage, how many miles on the truck? ZF HP24 not known to have 4th gear issues, would be unusual. Code occurs when output shaft speed does not match expected output based on gear selected and engine rpm. My guess is maybe front clutch is slipping but manifest as a 4th gear issue. Recommend you get a complete trans from a breaker.
Camel Trophy
Joined: Sep 2017
Posts: 3,818
Likes: 1,337
From: Mission BC Canada
Code P0734 4th gear incorrect ratio
Hi Richard,
I just realized that we put new tires on her
and soon after this code popped up. Correlation between the two?? I work at a parts store so I ordered another O2 sensor and will put it on this weekend. Could the bad O2 sensor trigger the P0171 Fuel imbalance code? The P0150 code was for the O2 sensor. Sorry my bad.😞 Thanks
I just realized that we put new tires on her
and soon after this code popped up. Correlation between the two?? I work at a parts store so I ordered another O2 sensor and will put it on this weekend. Could the bad O2 sensor trigger the P0171 Fuel imbalance code? The P0150 code was for the O2 sensor. Sorry my bad.😞 Thanks
P codes
Best practice when you have a one bad 02 is to swap left and right, that way you can confirm bad sensor vs bad wiring or bad something else.
Bad speed sensor does not just give fault in fourth, it gives fault for all the gears. Incorrect ratio is typically a sign of clutch slippage, how many miles on the truck? ZF HP24 not known to have 4th gear issues, would be unusual. Code occurs when output shaft speed does not match expected output based on gear selected and engine rpm. My guess is maybe front clutch is slipping but manifest as a 4th gear issue. Recommend you get a complete trans from a breaker.
Bad speed sensor does not just give fault in fourth, it gives fault for all the gears. Incorrect ratio is typically a sign of clutch slippage, how many miles on the truck? ZF HP24 not known to have 4th gear issues, would be unusual. Code occurs when output shaft speed does not match expected output based on gear selected and engine rpm. My guess is maybe front clutch is slipping but manifest as a 4th gear issue. Recommend you get a complete trans from a breaker.
P0150, P0734 and P0171 sorry, thanks.
Camel Trophy
Joined: Sep 2017
Posts: 3,818
Likes: 1,337
From: Mission BC Canada
@MRGMAN
On the P0734 I knew that was familiar - check all of your connection from the air box back. That one can show up from a loose airbox or other conenction- I know makes no sense but there it is it is related to engine air flow issues as well as transmission issues.
You could have a bad MAF as well which has been known to cause all 3 codes.
My original post on this code https://landroverforums.com/forum/di...8/p0734-89114/
On the P0734 I knew that was familiar - check all of your connection from the air box back. That one can show up from a loose airbox or other conenction- I know makes no sense but there it is it is related to engine air flow issues as well as transmission issues.
You could have a bad MAF as well which has been known to cause all 3 codes.
My original post on this code https://landroverforums.com/forum/di...8/p0734-89114/
Bad maf
@MRGMAN
On the P0734 I knew that was familiar - check all of your connection from the air box back. That one can show up from a loose airbox or other conenction- I know makes no sense but there it is it is related to engine air flow issues as well as transmission issues.
You could have a bad MAF as well which has been known to cause all 3 codes.
My original post on this code https://landroverforums.com/forum/di...8/p0734-89114/
On the P0734 I knew that was familiar - check all of your connection from the air box back. That one can show up from a loose airbox or other conenction- I know makes no sense but there it is it is related to engine air flow issues as well as transmission issues.
You could have a bad MAF as well which has been known to cause all 3 codes.
My original post on this code https://landroverforums.com/forum/di...8/p0734-89114/
Hi,
that was the first thing I did was replace the MAF. Thanks
Mudding
Joined: Jul 2023
Posts: 121
Likes: 79
From: Dirty Jersey
Are your freeze frame short term trims rich?
If there's unmetered air getting in past the maf, maf can't do its job so your mixture will be off, which will trigger O2 sensor code.
Or if maf is reading wrong it could be doing same.
Everything might be doing their job and it might just be a big vacuum leak.
Just brainstorming. If you post your freeze frames maybe we can help pin it down.
If there's unmetered air getting in past the maf, maf can't do its job so your mixture will be off, which will trigger O2 sensor code.
Or if maf is reading wrong it could be doing same.
Everything might be doing their job and it might just be a big vacuum leak.
Just brainstorming. If you post your freeze frames maybe we can help pin it down.
Fuel Trim
[QUOTE=Roont;887339]Are your freeze frame short term trims rich?
If there's unmetered air getting in past the maf, maf can't do its job so your mixture will be off, which will trigger O2 sensor code.
Or if maf is reading wrong it could be doing same.
Everything might be doing their job and it might just be a big vacuum leak.
Just brainstorming. If you post your freeze frames maybe we can help pin it down.
Hi,
My Dongle isn’t that advanced and I’m 150 miles from any Land Rover dealer or Indy and nobody in this small Texas town wants to work on her. Thanks for the response. I swapped out the O2 sensor with another new one and got rid of the P0171, P0174 & P0734 but picked up a P0207 and a P0307 wtf. If I didn’t know better I would swear she’s playing games with me!
[/QUOTE
If there's unmetered air getting in past the maf, maf can't do its job so your mixture will be off, which will trigger O2 sensor code.
Or if maf is reading wrong it could be doing same.
Everything might be doing their job and it might just be a big vacuum leak.
Just brainstorming. If you post your freeze frames maybe we can help pin it down.
Hi,
My Dongle isn’t that advanced and I’m 150 miles from any Land Rover dealer or Indy and nobody in this small Texas town wants to work on her. Thanks for the response. I swapped out the O2 sensor with another new one and got rid of the P0171, P0174 & P0734 but picked up a P0207 and a P0307 wtf. If I didn’t know better I would swear she’s playing games with me!
[/QUOTE
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