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

 

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.

 

@MRGMAN post the actual code for the transmission there is one that tends to be something else.freaked my out the 1st time I got it until I did a lot of research and found it was another issue.

 

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

 

P0150, P0734 and P0171 sorry, thanks.

 

@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/

 

Hi,
that was the first thing I did was replace the MAF. Thanks

 

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.



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[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!
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