Here we go....

Right, definately no air leaks. Refitted standard intake and works fine.

Refitted new intake and deffo no air leaks, had it checked by my Indy.

We have narrowed it down after extensive testing to it only throwing the code when it is a warm engine restart.

I leave the car over night or a long period, it will start fine and run perfect. However if i stop for a coffee mid journey and restart her up after 5 mins throws the lean on both banks codes, reset the codes runs fine.

My Indy said it could possibly be an ageing MAF and the flow from the new intake is highlighting it.. ie too much cold air passing through too quick when it expects warm less dense air from a warm engine mid run..?

Any other thoughts..?

DTCFRZF P0171 & P0174

Fuel Sys 1 CL
Fuel Sys 2 CL
Load - PCT% 12.5
ETC (F) 19.9

Short FT1% 20.3
Long FT1% 19.5
Short FT2% 17.2
Long FT2% 19.5

FRP ( Psi ) 55.7

MAP ( in Hg ) 12.7

RPM (/Min ) 581

VSS ( MPH ) 1

IAT ( F ) 126

MAF (lb/Min) 0.681

TP% 5.5

 

Replied to your post in other thread.

 

Check brake booster vaccume line running from brake booster to intake manifold. Check tube running from EGR to passenger side exhaust manifold. Check vaccume line running from throttle body to crank case ventilation (PCV) on passenger side cam cover. Check purge valve to vaccume line fitting (drivers side next to strut tower.

 

All lines checked out okay, returned to stock for the miunute until i can spend more time on it.

 

Ran it today with stock air intake, and it only throws the P0171 code, too lean bank one. Short term furl trims are 5 or under but long term trims were in double figures.... so there has to be a vacum leak somewhere, any pointers on which air hose/assm could cause this....?

 

Hope you find it. The V6 is well known for vacuum leaks but it's pretty rare on the STR.

Let us know what you find?
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Though she's only presently showing bank 1 lean, check the seal on the air filter box, etc.

 

I have now swapped and refitted the modified intake/filter assembly back and forth several times to ensure correct fitments. I am only getting a lean code for Bank 1, and only after restart mid run.

Reset the codes and she will tick over/idle and drive fine until i stop and restart. At a loss at the minute as there is no obvious poor fitment or leaks.

I will book her in to my local indy and see if he can spend some time finding it. Hopefully the lean on both banks was a red herring and there is a vacum leak on one bank or a dodgy MAF.

Once rectified will report back, thanks for the input guys.

 

I had a vacuum leak where one of the intercooler gaskets failed and was causing the car to freak out at idle. Other than that, I haven't seen any problems.

 

Idle seems fine, only does it after warm start up.....

Start up first thing and go for a run fine, leave it all day start and go for a run fine, reset codes and drive runs fine.... which is why i am questioning an air leak.

I am going to change the MAF sensor anyway to rule that out as they are not overly expensive, if still there then i will have to get her stripped down and check all pipes and gaskets.

 

If only one side now has big LTFT then it's hard to see how it can be anything common to both banks (such as MAF).

 

The threshold is >18%, so if the other bank is slightly lower it can still have a common cause.

 

How does a properly working engine have 18% different fuel trims between the banks? Grossly worn injectors (doesn't seem to happen on these cars) or what?

 

He didn't say bank 2 has 0% ltft, or did I miss something? If that is the case, it could be the ECU, O2 sensors, exhuast leak (so more o2 molecules go to the o2 sensor) or as you say some clogged fuel injectors.

I just said if bank 2 would be for instance at 17%, it would not throw a code, only if you go over 18%.

 

Good points! Still, plenty of good threads about how to get data and what to do for these codes. Also, he did previously ask what trims to aim for and I said within 5% of 0.

 

My 03 STR has been behaving in the same fashion as the OP. Replaced all vaccume lines, EGR, charge cooler gaskets, etc., O2 sensors, etc. but to no avail. Picked up a warranty two months ago, now she's going to Jaguar for observation/repair.

 

Weird one... been okay on long and short journeys for the last 24hrs....!....The codes were either lean bank one or both banks, never bank 2 on it's own..!... so due to the sparodic nature i am changing out the MAF as a starting point and then working back. Should be here Monday so will get it in and report back.

As always thanks for your feedback and pointers....

 

Let me know how you get on....

 

Did the shop working on the vehicle bother to check the fuel pressure?

 

I believe my 03 STR has an intake manifold or blower leak. Will keep ya posted.