V8V Lean Codes - Can't Resolve

[cjm455]

I've had my 2010 V8V for 3 years now, and have had a lean bank 1 or 2 code for half the time. I've fixed a vacuum leak, replaced the O2 sensors & MAF sensors, checked running fuel pressure, run multiple injector cleaners, etc. but each time the code turns off for a few weeks, then comes back on. Now I have lean bank 1 & 2 codes and they aren't cycling off. The car starts perfectly, but has a rough idle at times and feels like it could stall occasionally when on my sloped driveway or a traffic light. While the running fuel pressure checks properly, it did seem to lose pressure twice as fast as a standard car when I turned the engine off.

A mechanic friend suggested I replace the fuel pump and/or fuel regulator valve, but it's a 10 hr job that requires taking out the drive shaft, so I want to try everything else possible before tackling. I welcome tips from anyone else who's been through this. Did anything else work? Did you have a similar issue a fuel pump or regulator fixed? Thank you!

[Go60 Jay]

Hi,

Do you know if it’s sensor 1 or sensor 2?

I had the same issue on bank 1 and bank 2, both were sensor 1 (primary cat).

In my case it was the primary cats failing. I’m going to do a post about it soon. Basically I had the primary cats removed, secondary 200 cell race cats fitted and remap. It now gives much better performance, a nicer pull and better fuel economy.

I strongly suggest you contact Mike at Bamford Rose. Even if it’s not that, he will at least be able to quickly diagnose the problem.

John

[cjm455]

Thanks for your reply. This is definitely something else I can look into while troubleshooting. I didn't think about the cats for the issue because I have codes P0171/P0174. Do you recall if those were your codes or if you had P0420/P0430 which are cat specific?

[BiggaJ]

Where in the UK are you located? if near Hampshire, I know Adrian at AHM Aston Martin will sort you out. He fits the 200 cell CATS and remaps to allow the engine to not throw error codes.

[cjm455]

I'm currently in the US but appreciate the recommendation. I have access to a shop for work I can't do in my own garage and was honestly trying to avoid taking to my local dealer because of pricing. It's odd each emissions system fix I do temporarily turns the emissions light off, even running fuel cleaner can turn the warning light off while in the tank, but it always comes back on. I was hoping someone on this site had the same experience or could share their symptoms of a failing fuel pump. While the codes don't suggest the cats, I will do some tests there too. Thank you.

[BiggaJ]

cjm455 said:

I'm currently in the US but appreciate the recommendation. I have access to a shop for work I can't do in my own garage and was honestly trying to avoid taking to my local dealer because of pricing. It's odd each emissions system fix I do temporarily turns the emissions light off, even running fuel cleaner can turn the warning light off while in the tank, but it always comes back on. I was hoping someone on this site had the same experience or could share their symptoms of a failing fuel pump. While the codes don't suggest the cats, I will do some tests there too. Thank you.

Try this guy Richard, he is based in the USA (Edit: he was based in the USA, now moved to Japan) and sometimes comes on here to post, he may be able to help you. He also has a lot of videos on YouTube that may cover what you are needing answers on.

https://www.redpants.lol/

Edited by BiggaJ on Thursday 21st August 16:43

[cjm455]

Thanks for the recommendation. I know exactly who he is and love his videos. They've helped me through several repairs.

[Dungman]

I would consider calling Mike at Bamford Rose. Very helpful and knowledgeable. Was happy to carry out ECU work for me with the unit posted to him so distance not necessarily a problem.