So my RDX is running great, but...

Running positive trims at idle, just under 10%. Starts near +6% and the longer it idles, the higher trims climb to max out ~+9.8%
Exhaust smells a little rich at idle.
Delta is running really close to 1, bouncing between slightly rich and slightly lean.
Trim turns negative under throttle and Long Term Trim will zero out when driving around town and on the highway.
Seems the + Trim is actually making it rich out the tailpipe, but the lambda is averaging 1.

Propane leak test came up negative.

I've pulled the IC and am doing a visual inspection of all hoses. The number of small hoses and in-hose valves is absurd. I'm currently forming a plan of attack...

Has anyone had a similar experience?
Ideas?

 

Are you observing a rich fuel smell on cold starts or after the car has reached full operating temp (same with the fuel trims)? Honestly anything +/- 10% is within the normal range of operation. I would not worry about the variance you are experiencing. If your lambda is staying at/near 1 during cruising and at idle, then you should be good. Lambda should drop some under heavy load. There are a million things that can affect fuel trims beyond possible intake leaks - O2 sensor accuracy, MAF sensor accuracy, fuel injector flow (designed vs actual), spark plug performance, air filter, and more.

 

Have new oil, oil filter, ATF, PS fluid, plugs.

The rich smell happens both on cold start and at idle, even after an hour of highway driving.
I can drive for an hour and let it sit in the driveway afterwards and both LT and ST trims will slowly creep from under 0 to ~+9.8 in about 20 minutes.
My mpg is good on the highway, but it's getting pretty awful around town, which is why I investigated in the first place.
I read an article on another site by a guy with an MDX that was doing the exact same thing. He never figured it out. Just ran it with bad gas mileage and rich idle.

 

Flashpro

 

Nope.
DIY smoke machine to find leak(s).

 

What is your city mileage now vs before? And perhaps other factors are at play, such as the switch to winder blend fuel, and colder temps in general. Rich smell on a cold start is totally normal - the faster the car gets to operating temp, the better. Cold oil harder to pump, cold cat isn't efficient, etc. But it shouldn't so obvious once it's at operating temp. If you're fully warm, idling with an indicated lambda at 1, and still smelling really rich, I'd question the upstream o2 sensor. I'll get some readings of my own after this weekend - it would be interesting to see another data set on this for comparison.

 

I was getting 13 mpg around town. So I'm down about 2-2.5 mpg.
I am using different oil. My mechanic was putting in recycled synthetic. I'm using appropriate Pennzoil. I actually thought my mileage would be better.
Gas is same mixture, I think.
Not smelling super rich, but rich enough to not sit in the car if it's idling in the garage with the garage doors open. And the exhaust tips are turning blacker.
Exhaust is factory Acura in great condition with no leaks.
I recently replaced the PCV valve which was completely shot and installed a new chain tensioner.
Timing chain is installed correctly.
Car pulls hard, boost onset is smooth, but boost cut on the top end seems more abrupt.
Small amount of oil from the turbo in the intake tract just before the turbo inlet, probably due to the faulty PCV valve.
It's not using oil at all. No external leaks

I usually ignore cold start data in my logging because its always going to be rich in open loop until it warms up.
Yep, lambda is good at idle after warming up and while driving around.

I thought it might be the O2 sensor, but is a bad sensor able to respond well enough to keep a stable lambda condition?
The +Trim at idle and -Trim while driving's got me thinking intake tract leak. I mean, it's boosted, so it will suck in unmetered air at idle, but lose metered air driving around town when the turbo kicks in...
Dunno. Just throwing darts.

Kicking myself for not checking the injector o-rings when I changed my plugs. (Iridium Laser)

I'd really appreciate some base line data.
Throttle position @ idle.
System vacuum @ idle.
Average town trim.
Average highway trim.
Low / Max warmed up idling trim (10-20 minutes of idle after 10-20 minutes of driving).

Any info, really, would be great.
I'm just using BlueDriver right now, so I'm limited in what I can track.

 

Homemade smoke machine revealed two leaks.
One atop the fuel pressure regulator - hose end was rotten.
One at the junction between the turbo inlet pipe and the resonance chamber pipe. These pipes have some flashing on the connector ends and aren't perfectly round.

Some smoke beneath the oil cap. Removing the oil cap released the pressure I'd built up with the smoker, so there's flow between crankcase and air system, but no other leaks.

Not a lot of pressure. Not much smoke.

Zero trouble codes.

 

Looks like it's the cat. Wide Range and narrow range sensors are mirroring each other somewhat.
However, that's supposedly how the system is supposed to work on some factory boosted cars.
Would appreciate someone comparing Sensor 1 Current (mA) and Sensor 2 Voltage (V) readings at idle.

I guess I'll just wait 'til trouble codes appear before moving on it.
Will be expensive to replace the cat and I'll want to rebuild and maybe upgrade the turbo at the same time.

 

13 mpg is pretty ugly - wouldn't call that normal unless you spend a lot of time in stop-and-go traffic. I just got back into town tonight - will try to get some data over the next day or two.

 

The lowest I have ever seen on our MMC was 11.9 a few years ago. We were parked idling a lot though.. .

Now, at about 70% highway we average about 21 or so.

13 is pretty low, I'd say city should run about 15-18 in the RDX.

 

Traffic/highway time split is 90/10 at the moment.
MPG seems to be getting marginally better. Need to fill 'er up, run a full tank and crunch the real numbers.
Since flushing the tranny, shifting into 2nd and 3rd have been much harder and at higher RPM.
Going over the intake tract and plugging the leaks, the turbo has been spooling at lower speeds.
Neither is great for gas mileage in a really congested, hilly town with constant road work and piss poor traffic management.

Any data will be greatly appreciated.