Just got the wireless OBD2 reader and tested it this morning. Here's what I got... The only thing I'm seeing that seems off is the n/a% for the #2 O2 sensors. My question is, if they're not getting a reading, why isn't the car throwing a code....

 

I recently took my MAFs out and cleaned them and this helped with a bit of the sluggishness.
What app are you using?
Torque pro has the fastest A/F and O2 readings that i've seen thus far.
I do notice that some readings work and other dont between Torque and OBD fusion so it wouldnt surprise me if that is your case with your fuel trims.
Try Torque pro.

 

I downloaded Car Scanner ELM OBD2 for ios. As this was one of just two free options in the handbook for the BAFX wifi OBD2 scanner I got.
Is Torque applicable to basically any wireless obd2 scanner?

 

The "Short term fuel trim (Bank x, Sensor 2)" aka PID $15 & $19, is not the same as the short/long term fuel trim. (PIDs $06 - $09)
They seem to be a static value, well at least on my car, as they haven't changed from 99.22% in the last five years.

 

Torque is Android only.
In my opinion the best iOS OBD app is OBDFusion.

Generally, any OBD type app will work with any OBD / ELM327 type OBD scanner.

 

You should check you vacuum levels with the AC on and off.
I believe I get about 22 inhg with AC off and about 19 or so with it on.
I suspect I might have a small vacuum leak.

 

Well that explains why I couldn't find Torque on the app store. Fusion is the one the scanner suggests is the best to pair with it, but I figured I'd try a free one and see how it worked.

I might have to check that too. I just did an oil change and inspected the throttlebodies and MAF's while under the hood. When I started up the car after to check for leaks, I revved it a little bit and heard a little whistle. It was in my garage with exhaust pointed out so the resonance in the structure allowed me to hear more of the engine noises than normal. I had the windows down all summer weather permitting and I never heard the whistle.

 

The problem is that most of the free apps are limited. I had to buy the advanced options of both Torque and OBDfusion. Well worth it in my opinion.
I ended up getting a Samsung Tablet that I keep in the car. It's entirely empty only for those two apps to make sure I get the best speeds as possible.

Whatever app you end up with familiarize yourself with it and your numbers this will come into play with later diagnostics.

I would like to make a thread on OBD baseline results/numbers as I feel most of these misfire issues can be diagnosed with these especially as finicky as these cars are with their fuel trims.

As a test you should monitor your fuel trims as you are going through the issue. For example I noticed that bank 1 on my car is a bit richer while this is happening which could point to a coil that's misfiring at this rev.
My theory is that in my car I have a coil tube that might be grounding during this RPM causing an ignition misfire however since it only happens at this rpm and under a certain load it will not set a code.

 

Would it be a coil misfiring or just bad plugs? I've seen some cars where one spark plug wears much faster than the rest for some reason. I still have to check them on my car to see if that's part of the issue.
What did you use to clean your MAFs? Is there a special cleaner for them?

 

Carb/brake clean for the MAFs.

As far as a spark plugs these cars come with iridium spark plugs. That's one thing I've never change on this car however it Could be my issue. I put a lot of faith in to the original Denso plugs and in all honesty it will be my last step. I would not like to add a set of fresh plugs only to gradually spoil them if that was not in the issue.

As far as a coils go, the coils are great however the tubes on the coils are not and dont like any liquids.
Like leaky valve covers that introduce a bit of oil or moisture through an engine wash.

Monitoring these trims will let you know if the misfire is fuel or spark

 

Makes sense to wait on the spark plugs, I thought they were slightly cheaper than what I'm seeing for them currently. Possibly remembering the cost of them for a different car.

What do you do to check the coils and tubes? All I've ever done is change plugs. I've never had to diagnose an issue like this before.

Maintenance records show that the valve cover gaskets were replaced shortly before I got the car. Could a hose have been cracked or something when put back together and is just now showing itself due to colder ambient temps?

I'll have to check what all the app shows in total. I might just go ahead and do OBD Fusion so I have more visibility. There's sensors that I know the car has that aren't showing up and readings that are just showing n/a..

 

For coils you'll need to remove and inspect, You can slightly lift them with the car on to see if you see the coils arcing from the tubes onto the heads. Inspect for moisture in the plug holes. Wouldnt hurt to check your plugs

Plugs are about $10-$13 for genuine ones, unfortunately I dont trust any online sellers on "geniune" plugs after buying 2 sets of counterfeit Denso and NGK plugs. This is a real issue and its a worrisome one being that some online sellers end up purchasing from other vendors and in all reality the copies are really well made up until the electrode. There is no copying the Iridium electrode. Anytime you see Denso plugs for less than $8 each beware.