2001 ford explorer 4.0 sohc P0171

My wife and I have a 2001 ford explorer 4.0 sohc with a p0171 code and I believe that's bank 1. I have already replaced the upper and lower intake gaskets. I now hear what sounds like an exhaust leak. Can a exhaust leak cause a lean code?

Thanks in the future.

If the exhaust leak is upstream or near the bank 1 oxygen sensor, then yes, it can cause a false lean condition

Hey Jay! Any chance you can look at scan data? Knowing what the O2 sensors and fuel trims are doing at different loads would go a long way towards diagnosing this code.

I think it's also worth saying that just because you have a bank one code, doesn't mean bank two is A-OK. It sometimes works out that both banks are running lean, but one bank happens to set a code before the other. Again, looking at fuel trims would help here.

Like Paul said, exhaust leaks are definitely a potential source of fuel trim issues. Just don't go nitpicking your exhaust too much - it's my experience that exhaust leaks needs to be pretty large in order to set lean codes.

Tyler wrote: Hey Jay! Any chance you can look at scan data? Knowing what the O2 sensors and fuel trims are doing at different loads would go a long way towards diagnosing this code.

I think it's also worth saying that just because you have a bank one code, doesn't mean bank two is A-OK. It sometimes works out that both banks are running lean, but one bank happens to set a code before the other. Again, looking at fuel trims would help here.

Like Paul said, exhaust leaks are definitely a potential source of fuel trim issues. Just don't go nitpicking your exhaust too much - it's my experience that exhaust leaks needs to be pretty large in order to set lean codes.

Here's a good video on the free channel that shows exactly what Tyler is talking about:

Can scan files be posted on here? That would give everyone a better chance on helping and understanding what his issue is. I"m new here so I don't know. I saw you can attach files at the bottom but what type?

If you take a screenshot and save it as jpeg or png you could paste it right in.
I know some of the members of the forum were/are using scanshare.com and linking to there.

Cool so am I.

Yeah, I use ScanShare whenever I can, great service!