I had the same codes, and my problem was a rubber vaccum hose underneath the inlet manifolds. I don't have an str, rather a v6, but this hose was underneath the inlet manifold (the plenum that my injectors were fit into). Hope this helps. Soapy water is good to use, but in area's you can't see too well, I spray brake cleaner while the car is on and see if there is a change in idle.

 

I had this same problem that drove me crazy until I fiqured it out.

Take your MAF sensor back out and inspect the rubber O ring around it. My O ring wasn't seating inside the tube correctly.

After I cleaned the o ring lightly lubed it so it wouldn't not tear putting it back in. Once I was sure it was seated correctly I screwed it down.

I have not had another code since.

Hope this helps.

 

ive had the exact same codes in my system for over a week now.. its really is driving me crazy..!! RP is the worst when your in the mood for some spirited driving.. ive done some research online and most seem to believe these "lean codes" have something to do with either the MAF, o2 sensor, or some sort of vacume leak..

what would be my first step here guys.?? my uncle cleaned the throttle body this weekend and also changed the TB gasket.. he said i should take it to the Jag dealer and have them put it on the IDS and maybe do an ECU(?) reset as that might clear the codes.. what do you guys think??

as always, any help greatly appreciated.

 

Use an OBD tool to read the fuel trims but before doing that check the basic OBD things:
1. that all the monitors are Complete (you may see this as P1111)
2. that the car is running CL (closed loop) on both banks
Get the fuel trims with engine warmed up, at idle and at 2500rpm, in Park.
FAQ on fuel trims: https://www.jaguarforums.com/forum/g...ed-quiz-49317/

 

Add me to the list! Wife called this afternoon and said her "oil light" came on and "restricted performance." (05 S 3.0L)
"Was it red or yellow?"
"It was orange"
"oil P would be red...you are home? How long did you drive it that way?"
"I think I noticed it 1/2 way home."
"Please get the manual and look up what it really was."
(calls back) "it was definitely the oil light...but it was ORANGE! The book says red, but I KNOW it was orange...what color is "Amber? thats in the book."
"Yellow"
So when I got home, she showed me the oil P light in the manual...so I flipped to the CEL light and asked, "Could this have been it?"
"Yep...it was on that side, too"

I just changed the battery last weekend b/c it was 6 yrs old and I feared something like this would happen....but this is all in the WRONG order!
Read the codes:
01 - P0171
02 - P0174
03 - P0171 P
04 - P0174 P
05 - P1111

My scanner doesn't do fuel trims, far as I know....$25 from amazon....
Dang...she's taking our eldest son to our daughter's university tomorrow for a looksee first thing tomorrow morning (5-6 hr drive)...I'm gonna have to give up my big Cat or the pickup for their trip. and go bug Motorcarman with hers.......


IP Sensor, EFT Sensor, TP Sensor

P0174

Engine misfire
Air intake leak between MAF Sensor and
cylinder head
Fuel filter / system restriction
Fuel injector restriction
IP Sensor fault (low fuel pressure)
Low fuel pump output
HO2 Sensor(s) (2/1, 2/2)
harness wiring condition fault
EFT Sensor fault (low fuel temperature)
MAF Sensor fault (low intake air flow)
Exhaust leak (before catalyst)
ECM receiving incorrect signal from one or
more of the following components:
ECT Sensor, MAF Sensor, IAT Sensor,

IP Sensor, EFT Sensor, TP Sensor

 

Bob will sort it but as it's the 3.0 it's likely to be that PCV hose that always perishes! Zillions of posts about it.......

 

Sorry about your troubles, Zane. Keep us posted on what the fault turns out to be. Good thing you have a fleet of vehicles available for your wife to make the school visit trip with your son. Here's to a safe trip there and back....

 

John and Jon,
Thanks. Is the PCV the one coming off the intake hose, snaking under the manifold and terminating mid-span of the right side cam-cover? Or the one with the "quick connect" at the bottom of the manifold just aft of the TB? Or somewhere else?

I cleared 'em (might not have been my best move...but hey! if it's real...they''ll be back.) and will try it out on the kid-school shuttle today to see if they return (10 mi. round trip mix of highway / stop-n-go. Didn't think she should attempt a 500 miler in it, though.

Sent McM a note asking if WDS will tell more or if I should just start digging for vacuum leaks or MAF issues failing that? No response yet but I suspect I'll have it down there hooked up to his machine and better yet, his considerable knowledge within the next day or two if he's available.

Spare-car is a luxury I keep telling myself is really a necessity AND I keep telling myself I can afford it (both arguments are suspect) but any of you married guys know the climate....Momma's (fill in blank - car, washer, dryer, dishwasher, etc..) don't work..momma ain't happy...momma ain't happy....nobody happy...lol
seriously..she's taking it pretty well....but having a spare does allow one some confidence to tear into whichever one is broken, knowing even if it's over your head, you can still get to work or run-down parts.

 

I agree on the importance of a spare vehicle as long as it is financially justifiable given the family circumstances. Like you, I've had as many as five vehicles at one time spread across just two drivers in the family. While it was fun, the expenses were ridiculous and completely unjustifiable, and after a while I really got sick of all the routine maintenance involved and the way my vehicles were gobbling up my spare time. It's no fun spending all Saturday afternoon and into the evening washing five cars, especially when you have a football game to play on Sunday afternoon and you really need to rest your back to allow for maximum performance on game day. So I cut our fleet down from 5 in the early 90s to 4 by the mid 90s and then 3 from early 1998 until late 2002 when I actually got us down to just a 2-vehicle family for the first time since the early 80s. I had been working from home since November 2000 and knew I could make a 2-vehicle plan work with little difficulty. Stayed that way until I purchased the S-Type for a relative pittance in December 2008 during the depths of the recession. Three vehicles work well for us right now. One truck, one SUV, one sedan, so basically any requirement is covered for the job at hand....

 

I haven't had the code come up in almost 1500 miles until yesterday. I always just drive normal, I don't baby it but I don't go overboard. last night I did for the first time really get on it and low and behold p0171 RP popped up.

I cleared it and all was good. This morning it was running fine,I decided to try it again after a heavy foot I got the code and RP again.

I personally think it is the MAF. I am 95% sure. I am going to clean it again and see it it can stand a heavy foot,if it does I will be ordering a new one. When you have to clean it every 2 weeks to keep from throwing codes its time for a new one.

 

WDS won't help if it's a hose that's leaking.

There are posts about the hose - try Search on
hose
elbow
leak

I don't know the 3.0 engine in enough detail (I have an STR!) to say just where but I believe the hose is under the intake (Search will reveal). Depending on age etc plan to change gaskets and at least think about IMT O rings if not yet done. Easy DIY, cheap parts.

Getting BOTH codes means it's likely an air leak at a common point. Getting only one code means look elsewhere, would be my thinking.

 

That was my thinking too, b/c both banks affected. Changed IMT's a month or two ago but did short route on this one....03 was due plugs so it got long route and complete vac. hose inspection.

Update: forgot to mention last night while checking integrity of the vac hose that mates to the intake hose just upstream of the manifold/tb interface...(pushing on it) I noted very slight movement of the intake hose at the manifold. Clamp was pretty tight, nonetheless...I loosened it, pulled intake hose, re-seated and firmed-up the clamp. Didn't really think it was a problem but can't say 100% no-way-no-how it wouldn't be a vac. leak...that would be behind the MAF which is one of the possible faults....so maybe....just returned from kid-duty 30 mins on, shutdown and a restart for prepositioning at home. No codes returned. Only revv'd to 6k once on the jaunt.

Jon, I guess I'm technically at 7 for 4 drivers (one ea. off-site) but discount the Jeep as long-term down..so 5 for 3 actually at the domocile...maybe 4 as myself and my youngest son are the only members with sufficient self-confidence to be seen out and about in the Merc! (It's my "Denny" if you've seen "Man from Snowy River") but have a budding driver-in-waiting....so no end in sight. Behind on plans to return the Jeep to service and eldest son has his heart set on my pickup so that will be advantageous vs. buying another used car....but "I'm NOT READY TO LET GO! yet..dangit!"

 

Easiest thing would be a USB ELM327, about $20, plug it in and read fuel trims.
Both sides PCM adding fuel = lean conditions detected = air leak (*) or misfires.

(*) = at a location common to both banks.

If you hear hissing, leak found.

If you like, short squirts of propane (or similar), trims jump, leak found.
No jump anywhere = leak is where the propane isn't going (perhaps under the intake). Or it's not a leak.
Don't cause a fire!! Beware moving parts, too.

 

what should the fuel trims read is working correctly vs incorrectly..I REALLY wish we could get some common charts up with all the stats.

 

This procedure might help http://www.gusglikas.com/images/Auto...otos/P0171.pdf
This was my situation on my 2000 s-type 3.0 2000 3.0 S-Type Vacuum Leak

I do agree with jagv8 with the exception of using flammable products around a running engine. I use TB cleaner and when the engine begins to choke you found it. Jagv8 is braver than I am!

 

See https://www.jaguarforums.com/forum/g...ed-quiz-49317/

But: just read trims and tell us them. At idle and at (say) 2500rpm, both in Park.

TB is almost certainly wiser but next thing people use it to clean their TB and cause grief

 

here is my fuel trims they varied some.

short term bank 1 +3.9 then @2500 rpm +9.4

long term bank 1 +17.29 @ 2500 rmp +10.2



short term bank 2 +4.7 @2500 rpm +9.4

long term bank 2 +15.6 @ 2500 rpm +6.3

 

Classic air leak!

The LTFTs are biggish + (means adding fuel) but reduce at higher revs (far more air going in so the leak no longer takes as much correction).

Now you "only" have to find and fix it

 

thanks jagv8. Do you think I should be looking for a big air leak? I am going to be replacing the fuel injectors this weekend and will have a good look at everything around them.