I am getting the codes P0172 and P0175. I have replaced all the spark plugs, coils, and the MAF sensor. What else can I do to fix the problem?

2005 Jaguar S-Type R
145,000 miles

 

Could you check the codes again? P0171 bank 1 is lean and P0175 is bank 2 rich

 

Yes, definitely P0172 and P0175. What are bank 1 and 2?

 

Left side right side

 

I would suggest adding a can of BG44K to your fuel tank ans see what takes place first. This fuel additive is a little hard to find but it is the best on the market.

 

Check the cats as they can cause rich running.

What is stored for the codes in the free frame data?

Sounds like the codes come back if cleared - how soon?

Have a look at fuel trims, too. Hot engine, parked, at idle & then rev to about 2500. (The idea is to get more data.)

Worth checking fuel pressure.

 

Clogged intake or filter can cause these two codes. It's something common to both banks.

 

1) Check the cats as they can cause rich running.
What do I check on the cats?

2) What is stored for the codes in the free frame data?
Where do I find the free frame data?

3) Sounds like the codes come back if cleared - how soon?
yes, the codes return within 50 miles driven.

4) Have a look at fuel trims, too. Hot engine, parked, at idle & then rev to about 2500. (The idea is to get more data.)
What are fuel trims and how do I check them?

5) Worth checking fuel pressure.
I am working on this.

 

I added the BG44K and ran through a tank of gas. Now I am only getting the code: P0172 Bank 1 system too rich. Should I run another can of the BG44K?

At one point I replaced the lower O2 sensors. Would replacing the upper O2 sensors help with this?

 

You have a vacuum leak. The codes will return.

Look at the P/B hose connection to the manifold. It has an O-ring that will be hard and rotten by now. If it's not leaking, it will in the future.

Have you changed the under SC hose yet? Because that's an excellent time to repair that vacuum elbow too. Same stuff has to be removed.
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Looks rich not lean so probably not a leak.

If you can't follow existing posts (and those from Search) sounds time to find a tech - jag indy if you can.

Sorry - typo "free" -> "freeze".

 

Oops! Thanks JagV8. I got my codes swapped. The rich codes we don't see often.
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I know this sounds crazy, but check your battery. I was getting a series of strange codes when someone suggested that I check the battery. I was getting 11.5 volts across the battery with the engine off. The battery was 5 years old. I replaced the battery, reset the codes, and haven't had a problem since. That was about 2000 miles ago. I cannot explain why a marginally low battery voltage causes the problems.

 

It sags and both upsets the modules and makes a poor spark via the coils

 

The battery is only about 6 months old. I did check it and it is fine. Thanks!

 

Not sure what you are meaning here? I have followed existing posts and searches. Maybe I am not looking in the correct places which is why I am asking for direction. The last thing I want to do is send it to a shop so that they can keep it for another two months and charge me out the nose for their own mistakes.

 

Working on and fixing modern cars efficiently and inexpensively involves learning very different methods than were used in pre-OBDII days. If you're not familiar with the terminology and troubleshooting procedures, your choices are either learning them (starting with the basics is mandatory), or seeking out someone who does.

The old days of 'hunt and peck and hope for the best' are pretty much gone.

 

FYI

Link http://jagrepair.com/images/AutoRepairPhotos/P20003.PDF

 

THANKS!!!

 

Did you use an OEM MAFS? The three main things that will cause a rich code on both banks are the MAFS, fuel pressure regulator, or coolant temp sensor (which would likely cause another code, but not always).