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View Full Version : I give up!!! Recurring CEL's IACV and TPS issues, aargh



rad rex
03-04-2009, 12:07 AM
Just a quick rundown of the issues (99 Legacy GT phase I DOHC) That I'm putting up for sale once I can clear the CEL's

I'm throwing several codes...

Front and rear 02 sensors
Idle control system malfunction
Purge canister
EGR solenoid


I replaced both 02 sensors with good used OEM ones from the local yard, codes still there. Replaced EGR, code still remains. Replaced the IACV, made sure it was clean and used a new gasket. I'm still throwing a code for the Idle control.

Here's my first Q (among many). I tried reading the duty cycle from the IACV and couldn't get a reading. I unlugged the IACV while the car was running and the idle didn't change, I still couldn't get a duty cycle reading from the plug with the car running. Should the car idle at all with the IACV unplugged?

I manually set the IACV so that it idles around 1000 RPM. It runs fine, so I'm thinking of just selling it as is. The 02 sensor codes are baffling me since I just changed them and there are no broken wires. I have no idea what to do about the EGR, is there and EGR solenoid as well as the EGR itself?

Any thoughts?

rad rex
03-04-2009, 09:34 AM
Figured out there is an EGR solenoid, as well as a purge canister solenoid. I am wary however of just throwing more parts at it

I've contributed to the forum, how about a little love back? anybody??

jey
03-04-2009, 10:19 AM
The car will idle with no IACV. Do you have the plunger style IACV on the throttle body? The plunger should move when you push on it - I've seen an IACV freeze up completely before.

How do you know the O2 sensor from the junkyard is any good?

Combination of IACV, Purge Control, and EGR makes me wonder if you have a vaccuum leak somewhere. Have you looked over all your vaccuum hoses?

Where are you located, and is your car an automatic of manual transmission? If you're selling I might be interested in buying, CELs and everything :)

rad rex
03-04-2009, 09:20 PM
Sadly I'm a bit of a haul from you. Maine to be specific. But if you REAAALY want it I won't argue, it's a black 5MT GT wagon with 180K

You are correct that both 02 sensors could be bad.

The IACV is the kind you can move. I actually aligned the TPS and then set the idle by moving the IACV. The TPS would only show 4.0v with the throttle fully closed. It's against the stop to get that reading.

It runs fine, I will most likely sell it just like that