Hello Folks,
About 20 miles after adding a bottle of Fuel Injector Cleaner to the gas tank of my 2005 STR I stopped at the auto parts store for my third trip to get wiper blades that fit (another story). Upon startup the amber check engine light came on followed by “Restricted Performance” message. Once home, I could not find my new but never used ELM327 so I had to buy a new standalone unit from Harbor Freight. I’m new to reading codes but I found P0171 – too lean Bank 1. There was no P0174 code which to my untrained eyes points to something unique to bank 1 like dirty or faulty oxygen sensors. With work obligations, so far I’ve not yet found any vacuum leaks and after cleaning the MAF the light and message still appear. This weekend, I’m going to try to learn how to read the fuel trims and will take the opportunity to replace spark plugs and fuel filter as well as inspect the O2 sensor(s) and even clean them if possible. The car operates fine however I’ve been driving my 1972 XJ6 to work as it could use the exercise.

 

Hmm, weird that you only have one bank lean, but it could be an O2. How many miles are on the car? I'd replace what you are going to do, reset the code and see if it comes back.

 

Until you read the LTFTs you're guessing. They may both be high but bank1 just a bit higher thus the code or ... well, read 'em

 

Have you checked the front, lower manifold hose? It's an elbow that is notorious for cracking. If you're gonna have things ripped apart, may take a peak.

 

With the engine running I did manage to pull the following freeze frame data:


DTC FRZF P0171
FUEL SYS1 CL
FUEL SYS2 CL2 ?
LOAD_PCT(%) 5.9
ECT(⁰C) 93
SHRTFT1(%) 12.5
LONGFT1(%) 12.5
SHRTFT2(%) 4.7
LONGFT2(%) 7.8
FRP(kPa) 414 ?
MAP(kPa) 20.0
RPM(rpm) 1297
VSS(km/h) 68
SPARKADV(⁰) 10.0
IAT(⁰C) 26
MAF(g/s) 5.25
TP(%) 3.9 ?

Tomorrow I'll have some time more closely look for any vacuum leaks. The I'll clear the code and give it a good run to see what shows up.
thanks,

 

Update. It was a bad upstream O2 sensor. Replaced the O2 sensor and after about 50 miles the code has not returned. Whereas the code did return after 1)cleaning the MAF sensor; and, 2) replacing the fuel fliter.

Car has 85,000 miles and I might soon go ahead and replace the spark plugs since I just bought them after the P0171 code appeared.

Now that the S-Type is ok, I'll be returning the 1972 XJ6 to dormancy in the garage after repairing an overflowing middle carb on my triple HD8 setup.

 

Hello David, re: code # 0171, There is a very extensive, complete, soup to nuts, what didn't work and what eventually did work for solving this 0171 code situation by a member with the handle/name of 'magmedia' Really excellent with photos and everything. He found after extensive diagnosis and changing of the fuel filter....and other things that the problem was a cracked plastic tube connector on the passenger side of the engine. Solved with a blister pack of 'tubing connectors' from NAPA.

photo's and every thing to explain your (and my) problem and solution.

Best to you.

 

So here's perhaps a different take on the whole P0171 and P0174 (left and right bank too lean) code.

I'm a pretty new, but learning fast, '03'S T R one owner dealer maintained sold to be for a fair price, love the car. That being said, my first car, ever, was a 1957 XK140 DHC.....loved that too. I came to understand that real 'Jag' people don't have a real problem tinkering with their cars. If you do (have a problem in the tinker department) then you better have very deep pocket, tons of patience, a back up car, and an understanding (or no) mate.

Back to the codes in question. Here's a suggestion for you. If you hear a 'clicking' under the hood that sounds like an old style tappet or even a valve then your problem is probable in the injectors. If you can have your car 'smoke tested' ....(they inject smoke and look for a curl of smoke leaving some obscure hole/area, etc. ) they that's a good idea and will find any illusive, hard to find, pin holes or larger. You can also start and run the motor with any and all 'extras' turned off, like AC etc. and spray 'starter fluid' around distinct places in the engine bay. If there is a vacuum leak the idle will increase. If the 'smoke test' (about $160.00 or 1 1/2 hrs....so says the local none dealer wrench) and the starter fluid test bare no fruit then listen for that clicking.

If you are hearing the/that/a clicking in the motor then one or more of your injectors isn't functioning properly. Having one or more of your injectors will, on the odd numbered cylinders, initiate a 'lean' or P0171 code and improperly functioning (one or more) on the even number cylinders, will initiate the P0174 code.

You can replace the injectors (Auto Zone $30.00 ish each) or have them professionally cleaned.....sonic something or other for a price of around $18.00 to $28.00....this should solve A. the 'eternal' hunt and B. the P0171 and P0174 codes.

I bought my 'new' 03 STR with 112K on it. In the 4 months I've owned I've replaced the 'J' box, had new, read 'no charge' complete ZF trans and torque converter installed by the Dealer (the 9 month old 'new install' from Jag failed and they honored the warranty, as required by Ca. law btw) a new set of OEM Iridium spark plugs and now I'm looking at all new injectors.

I've been told by what I consider to be reliable, trustworthy, honest sources that the life span of injectors is around 100K before needing professional out of the car sonic cleaning. The life span of Ignition Coils being around 80~85K miles....then in and out a new set. Plugs around 100K with the 'J' box being about the same thing, 100K ish.

The only thing that's left for me is the injectors.

By the by......I have 495K+ miles in air cooled 'P' cars (74 911 Carrera, 78 911 SC, 95 911/993 Carrera C2) and it was a fun afternoon when this (now) grey haired 'dude' in the Quartz '4 door sedan' choose off a young man and his, very cute, girl passenger in their camed up new, very pretty and loud, Mustang.....took off....his pipes and cam roaring and 'cleaned his clock'!! I'm not sure he'll ever tell that story but I'm very sure I'll make up for his reticence!!....

Bottom line: love my STR....I feel like both the Jag and I are older and 'more mature' but under it 'all' neither one of us has really grown up!!

 

I can't recall even one person whose lean code was due to injectors.

Anyone think so?

I've heard of RICH codes with faulty injectors, though also don't recall any on an STR.

 

You did read that David's problem was fixed by replacing the O2 sensor??

Not sure what you were trying to answer?

All injectors make the same noise. Try a DI engine sometime if you really want to hear a clatter!! Very much like a Diesel.

As JagV8 said we don't really get many problems that are injector related.
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