Got a 2002 S-type R thats flagging Bank 1 and 2 running lean, this can be seen when reading both number 1 lambdas which are just sitting flat at 0.2/0.3v's

Know this will be down to a Vac leak I know but which pipes are common to split on these engines? Only picked it up today and went into limp mode on the way home.

Cheers

 

I thought the STR was introduced in 2003? Do you have the 3.0 V6 or 4.0 V8?

Definitely agree on vacuum leak - Engine info will be helpful for us to assist - thanks!

 

In the UK STRs were introduced in 2002.

 

They're wideband so sitting at a voltage is normal. What are the LTFTs at idle & 2500rpm (in P or N)?

Single most comon problem is air box (not fitted properly or possibly wrong filter inside). Next is faulty MAF. Trims will prove which it can / cannot be.

 

Go with the advice of all who's posted, especially jagv8's air box check. If narrows down to vaccume leak than I'm likely someone to contact. I've performed repairs to all possible causes due to: swapping in all new vaccume lines, EGR and its exhaust manifold tube, and exhaust system.

 

Sorted now, was a vac hose that has come off in the inlet manifold. Causing air being drawn in after the MAF.

Thanks everyone.

 

Excellent!

 

Good Deal!

 

i just had the p0174 bank 2 too lean came on with restricted performance..

 

I have an S type 3.0 V6
I wanted to share my experience with you all. I got po171 and po174 on the ECU. I cleaned the MAF sensor and checked the pipes for breaks but everything seemed fine. The idle was rough, sometimes even stalling when stationary. I could hear some hissing sound coming from under the manifold so decided to take it to the local garage. After inspection they confirmed the problem to be linked to the inlet manifold gaskets. They also asked me if I wanted to replaced the plugs while the plugs were exposed. It seems that the garage who did the previous service only replaced half the spark plugs . Apparently a lot garages don't change the sparks plugs covered by the manifold due to the extra work required.

 

That's all very well - but this thread is about the STR and it has an entirely different set up (much easier to change all the plugs).

It's also a very old thread so best left as-is.