What is this, and what does it do?

[flair1111]

what is this part ive circled (red) in the pic?

for about 3 months my wifes 02 has had a sound coming out of the tail pipe that sounds like a rod knocking, but yet muffled sounding, kinda blunt and dead sounding.

today i was checking to make sure she didnt have any leaks since coming out of the body shop 3 weeks ago and i heard this sound up front. i just knew it was a rod for sure, but still was a bit blunt sounding. after putting my ear closer to the sound i noticed it was coming from this piece. i touched the piece and i could feel it bumping. i pulled the rubber hose off (blue arrow highlight) and the sound stopped. i put the hose back on and the sound is still gone. at the tail pipe the sound is gone. engine didnt run any different when hose was off. no noticeable difference in rpms or anything, just the sound is gone now.

does this need to be replaced? what was the sound and why?


PICTURE

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am an expert at MS Paint if you want to hire me to do some work.

 

[tjkj2002]

That is the EVAP soliniod,activates the EVAP system.The hose with the green cap on it is the leak test fitting by hooking up a smoke machine you can find leaks in the EVAP system.

EVAP/PURGE SOLENOID
DESCRIPTION
The duty cycle EVAP canister purge solenoid (DCP)
is located in the engine compartment. It is attached
to a bracket located between the battery and the
Power Distribution Center (PDC). The EVAP system
test port is located near the solenoid.
OPERATION
The duty cycle EVAP canister purge solenoid (DCP)
regulates the rate of vapor flow from the EVAP canister
to the intake manifold. The Powertrain Control
Module (PCM) operates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the solenoid.
When de-energized, no vapors are purged. The
PCM de-energizes the solenoid during open loop operation.
The engine enters closed loop operation after it
reaches a specified temperature and the time delay
ends. During closed loop operation, the PCM cycles
(energizes and de-energizes) the solenoid 5 or 10
times per second, depending upon operating conditions.
The PCM varies the vapor flow rate by changing
solenoid pulse width. Pulse width is the amount
of time that the solenoid is energized. The PCM
adjusts solenoid pulse width based on engine operating
condition.

 

[flair1111]

ahh. so that must be the leakage code i got. i was looking for actual gas leakage. the rubber hose is dry rotted a bit. i bet thats it.

 

[Powerslave]

Yeah, replace the hose FIRST, then clear the code, see if it comes up again...

 

[hyde]

P441
I had this forever. It is gone now, it can come back anytime. I had to replace it, I never did.

 

[SDLiberty]

P441
I had this forever. It is gone now, it can come back anytime. I had to replace it, I never did.

Yeah had the same code and check light come on. Went away on its own. Thought the check engine light burned out at first, but it still comes on when i first start it. If the light is not on is the error code still there?

 

[hyde]

Yes, it retains the error code. You can do the test on your 04 by cycling your ignition ON/OFF/ON/OFF -> ON and then leaving it in ON position for it to go through codes. ON (not RUN).