JoJoB3

Ok, so we have a 2002 Acura MDX here and Im getting what seems to me to be EGR related chevk engine light - VTM4 + Check Engine Light (VTM4 goes away next off/on, CEL stays on).

Reading vodes: several varied misfire codes + P1399.

I reset/clear codes and it eventually comes back two or 3 starts later. Also, really only comes on at idle. Never see it cone on at friving speeds.

Now I've cleaned the EGR system (several times, top to bottom, not just the EGR valve itself. I put a new EGR valve in well (standard motor products 02 EGR valve on Amazon). No fix, keeps coming on.

Must be something else here (although the issues DO point to the usual EGR sys related). Anyone been down this road before and found other culprits for resolve?

200k mi and it runs very well (only seeing CEL VTM4 lights...but runs great, strong).

Bosch iridium plugs were done 15k ago (was thinking of putting in the NGK Iridiums in case it's related (but really, it shows no signs of running poorly).

Front O2 sensor going bad/sketchy perhaps (though seeing no O2 related codes here).

Thanks for any advice

frankjnjr

FWIW: I would do two things immediately: (1.) Get rid of the Bosch plugs, and install the correct OEM recommended plug. (2.) At 200K, if the front 02 sensor is questionable, replace it as well. If," Now I've cleaned the EGR system (several times, top to bottom, not just the EGR valve itself.", every part, {Gasket) has been properly installed, replacement of the correct plug, and functional 02 sensor, should correct the problem.

stevekozak

frankjnjr

Spark Plug (PZFR5F-11) (Ngk) If you visit an on-line Acura OEM parts seller, for example, ( Delray Acura OEM Parts ) , you can look up any available part, for your 02 MDX. Just type the part you are looking for, into their search engine, and the correct part, will be listed, along with the OEM part number.

stevekozak

Thanks, Frank! That is good info to have! My MDX is a 2012.

JoJoB3

Just an update to the post.

At this mileage, and after shoring up the EGR sys, I suspected the coils. They were orig and after a little hawing over I decided to try new coils (all around). Bit pricey but not much.
I also didn't like seeing the Bosch sparks although they've had a meager amount of miles, so I installed 6 new Denso PKJ16CR-L11 Double Platinum ($4.35ea add-on item at amazon )
No more constant CEL, and it's a noticeable improvement on the feel at idle and throttle.

That said I think I still might change out the upstream O2 as Franjnjr suggested. I'm not getting O2 related codes but it's also quite old and I'm curious to see the results of swapping in a new Denso.

thanks all