P2187 Error code Maserati 4200 Coupe

[julianmerak]

Hi, I bought a 2005 Maserati coupe last July and the car’s settled down nicely. However, if I accelerate spiritedly the check engine light will come on within a minute or so telling me that the bank 1 is too lean at idle. The long term fuel trims are not perfect typically showing over negative 10% to negative 20%.
If I have an unmetered air leak where should I be looking or are my lambda sensors likely to be the issue? The new lambda sensors I bought just in case seem to have different plugs on them to what’s currently on the vehicle. The current ones at the front have a flat 4 plug attachment which doesn’t match up to what Eurospares supplied . What do I do to fit a different plug?

Any thoughts gratefully received!

Julian

Ps, car runs well so obvious issues apart from the check engine light getting triggered

 

[TimR]

Mine loved throwing up codes before I replaced the entire intake duct from airbox to throttle body. Once the air ox has been hit from below, it seems realigning the ducting isn’t as simple as it might seem without some contortion, and a couple bumps later, it springs a leak…?!
My 2006 4200 (EU4) has o2 plugs like this upfront…

 

[TimR]

Rears look like this ( I hope I got this the right way round)

 

[TimR]

EU3 have different positioning of sensor wiring, so if your front plugs are under the rads, you have EU4 ( cats in headers) No idea if the plugs are different however…just speculating you maybe bought the wrong ones…? Hopefully of some help to you….
Maserati would insist the O2 sensors were changed by now I think. Even if you have no reason to suspect they arent working.
I did mine. People don’t, presumably cos they aren’t cheap…!

 

[conaero]

The intake rubber bit are failing and splitting so that’s the first place to test.

If you have an intake/plenum leak sparky brake and clutch cleaner around, give it 5 seconds and listen for a rise in revs.

Obs this is a source of ignition so do it on a cold engine and go easy. A fire extinguisher should be close to hand but if it does catch it usually just flashes and goes out.

If ok start checking the obv stuff, plugs etc. clean the throttle body too and don’t put your fingers inside it with the battery on, your pointing days will be over.

I would put my money on Lambdas though.