Mass Air Flow Sensor Voltage

[jlglr4]

I’m not sure. Your o2 graphs are not what I’m used to seeing, but both sensors seem to be oscillating. That doesn’t necessarily mean one is not bad (they can get slow to respond throwing off your fuel trims). But it’s not likely both would go at once. I think bank 2 fuel trims look wonkier than bank 1, so you could try replacing that o2 sensor - or just replace both sides while your doing it.

How many miles on the spark plugs?

Could also check the purge valve. If they fail open, they can create a rich condition by allowing fumes from the tank into the engine - especially if you top off the tank too much. It’s a black stiff plastic hose that runs along the drivers side of the engine with one end that dumps into the intake. With the engine off, disconnect it and blow into the end of the tube - should be closed with no air flow.

Leaking injector is another possibility, but I think you’d have some smoke at startup (fuel leaking into the cylinder after shut down burns off when you start it up).

The other thought I had was that the vibration is not really a misfire. Hesitation sounds like a misfire. Bouncing - not so much, but I don’t really know what you mean by bouncing. If engine mounts are failing, you might get some vibration in the engine at certain RPMs. If LCA bushings are worn, you might get some vibration at certain speeds. But this won’t cause any hesitation in power under load.

 

[ftillier]

Have you run a bottle of injector cleaner (bg44k)? Unlikely to be the culprit but maybe...

 

[Rebar 911]

I have run several bottles of injector cleaner. I don't know when the spark plugs were last changed, if ever. I ordered new ones and will start there. Gas mileage is getting ridiculously poor.

 

[scapistron]

After you do the spark plugs, pull them back out and visually inspect them after several miles.

Computer in these is pretty good at detecting a misfire. Cleaning the throttle body is a good free option. If I were to start reaching for the parts cannon, I'd order new air flow sensors first. So easy to change too.

 

[Rebar 911]

After you do the spark plugs, pull them back out and visually inspect them after several miles.

Computer in these is pretty good at detecting a misfire. Cleaning the throttle body is a good free option. If I were to start reaching for the parts cannon, I'd order new air flow sensors first. So easy to change too.

I've cleaned the throttle body and the MAFs. Neither throwing a code. Spark plugs arrived today so will get those in this weekend. Hope I've got everything I need to get it done.

 

[Rebar 911]

I was only able to get the passenger side bank of spark plugs complete today and will finish the rest tomorrow. The photo is of three of the plugs I removed. They seem worn but not bad. And they are the NGK 7C model versus the 6C that were originally used which tells me they were changed at some point. Any thoughts about what you're seeing? Could these be the culprit?

 

[roverzac]

Hello, did you ever make any headway with this issue?

I'm getting the same thing, I believe. I have a noticeable loss of power and a roughness (feedback) I can feel in the pedal and steering wheel mostly at low speeds. It is negligible at 70 on the highway, and fuel economy seems to be better up there as well. I noticed it following an oil change. I was also due for a filter/fluid change on the trans and that offered no improvement. I also noticed maintaining or losing speed going downhill, unless I'm at a higher speed.

I get the same 32v sensor 1 on the iid tool, and the intake volumes seems close to one another.

 

[Rebar 911]

I have since cleaned the fuel injectors by hand as well as adding two cans of BG 44k. I also replaced all air filters, smoke tested for vacuum leaks reset the fuel calibration. Issue persists but my lean/rich readings greatly improved as did fuel economy. My guess is O2 sensors or more likely the torque converter. Neither of which I'm willing to do more with until the problem worsens.