emission codes

[Biggie]

Hi,

I have a 95 ATX and I'm trying to resolve DTC 335 - EGR sensor circuit voltage higher or lower than expected during self-test and 336, but says for trucks only-Exhaust pressure high 2. EGR sensor circuit voltage higher than expected. I was also getting DTC 337, but it hasn't re-appeared.

I have installed a new DPFE sensor as well as tried a good used PFE sensor and the other sensor which is directly below it and the DPFE sensor. I have no exhaust leaks and don't seem to have any issues with hose blockages. The EGR valve is old, but has no leaks. Car also has new catalytic converter, SHOSource catback and oxygen sensors.

Is my next step to switch the EGR valve? Kind of dread doing that. Is there a way in which perhaps I can clean it with it being on the car?

Does anyone have any ideas what else might be causing a problem?

 

[AREA 91]

I would clean the egr passages in the intake first.
If you search the forum, you will find pic's of the process.

 

[SHOdded]

EGR passages or EGR nostrils as they are fondly known

 

[Biggie]

Thanks for your replies. I gave that a go today. Just took some Seaform spray and started to clean the EGR lines. I added some seafoam to the gas tank. I'll grab some more and draw it in through the intake vacuum line as well. I drove the car quite a bit today after doing that treatment and now am down to just 335. DTC 111- System Pass is now displaying.