p2109 code after cleaning throttle body, rough idling

I had borrowed that scan tool and I ordered one it won’t be here until MON.

I created a live test checking LT fuel trims while at idle and they’re way high - check it out.

I wanted to run the test with the purge valve unhooked and plugged to see I the numbers would drop. I’m not sure why I had the commanded value there it kind of just stayed at that 35% range while at idle

 

Haha, sorry. Benefit of being 6’5” Too bad it didn’t fix it for you, I like to try easy stuff I most likely broke, first.

 

5 foot 7 ‍♂️

 

with the engine running:

 

engine off and key on (you can see where the engine was shut off):

 

Looks about right @ 4 gm/s
I’m with @Dm93 and the others, you may have a vacuum leak.

 

Hmm MAF looks about right but the fuel trims are high, do the fuel trims get better, worse, or stay the same while driving?

 

they don’t change so it’s looking like a fuel issue, right? that sucks

btw this is done with a scanner you can get for 20$ with a coupon and it’s bluetooth so everything is viewed from my iphone. Sure, it can’t send commands but i’m going to spend some money when I go that route.

It has a gauge to check for fuel pressure but it doesn’t seem to read. I am sure I am going to need a gauge to check mine.

 

I would expect them to get worse while driving if fuel pressure was low but it's definitely something to check.
The 4.0L has no fuel rail pressure sensor so you will not see that reading on the scanner, it has to be checked with a gauge teed into the fuel line.
You will need something like

$35 BETOOLL Fuel Pressure Test Kit 0-100PSI with 9.497.896.30 Fuel Line Fittings

this to check fuel pressure.

 

will this gauge work? looks similar - i’m reading the Haynes guide at this moment to determine the steps to reading the pressure. also, check
out these readings - this was me pressing on the throttle every 3 seconds for about 2 seconds or so - i’m seeing spikes in the LT fuel trim which I guess is getting worse as I accelerate. Also, the fuel gauge

 

more readings while pressing on the throttle

 

I don't think so, you need the quick connect adapters to tee into the line as there is no fuel pressure check port.

Fuel trims will do that on a snap throttle, my test would be a WOT pull while watching O2 sensor readings. If they drop lean and stay lean through the pull then that typically suggests a fuel delivery or MAF issue.

MAF accuracy can be checked by doing the same thing while graphing MAF, RPM, IAT, and Baro and entering the results in the calculator below.
https://atgtraining.com/atg-volumetric-efficiency-calculator/

 

I’ve got the kit you referred me to. Thanks a million! Once I figure out where to connect it I will do the tests (probably this weekend).

when I try to view oxygen sensor fuel/air, it’s only allowing me to view oxygen sensor 1?

maybe this scanner isn’t that great after all

 

You can tee it in at the quick connect in the pressure line going from the frame to the engine.

Yea something is screwy with scan data, you should have 4 AFR/O2 sensors available in data. The upstreams may be labeled as AFR sensors but there are 4 sensors in total.
AFR B1S1
AFR B2S1
O2 B1S2
O2 B2S2

 

on here they’re labeled oxygen sensor 1 fuel/air

but i’m not reading anything from o2 sensor 2, 3, or 4. I doubt I have 3 bad sensors im
only still getting the 3 evap codes p0171 p0174 and p0441. I’ll try to test with a different scanner and will use the photo uou shared and report back. Your input is invaluable. thanks

 

If you clean the throttle body too aggressively you can cause a vacuum leak where the throttle blade shaft enters the bore. There’s some type of moly grease or similar there to seal from the factory I believe.

 

Yea it's like the scanner can't even read the sensor PIDs properly, they should show numbers even if the sensors was totally dead.

 

Never seen this before, I know 1st gens had throttle bore wear issues but never seen that on a 2nd gen.
You can wreck the mechanism inside if your too aggressive with moving the throttle plate while cleaning though.

 

should the fuel trim numbers be dropping when increasing rpms? I don’t experience a drop when hammering the throttle - I also noticed this passed week it took me two tries to start the engine a few times.

 

i’m pretty certain I didn’t. I may have put a few scratches on the shiny surface using a soft bristle toothbrush and crc throttle body cleaner but I read that it’s no big deal.