Codes 335 & 336...93ATX.....Suggestions please!

[roswell998]

Consistently getting 335 on KOEO test with occasional 336 in memory but sometimes 111. No CEL has come on at all (bulb and circuit are OK).

Nostrils & passages thoroughly cleaned a few days ago. Also just finished both front and upper 60K. All electrical plugs & vacuum lines seem to be OK and properly connected (but you never know).

Suggestions will be appreciated.

 

[40BelowSummer]

335 DPFE sensor voltage higher or lower than expected.
336 Exhaust backpressure high / PFE circuit voltage high.

Diagnostic Trouble Code (DTC) 335 indicates the Pressure Feedback EGR (PFE) / Differential Pressure Feedback EGR (DPFE) sensor is out of Self-Test range.

Possible causes are:
• Damaged PFE/DPFE sensor.
• Obstructed pressure inlet hose(s).
• Garage exhaust ventilation system affecting PFE/DPFE sensor operation.
PFE/DPFE system can sense a lack of pressure in the vehicle exhaust system. An efficient garage exhaust ventilation system that is installed during KOEO test mode may generate a DTC 335.
• Remove garage forced ventilation system and properly vent to atmosphere.
• Rerun KOEO test.

If you did in fact clean the EGR passages well then I would replace the mentioned sensor, or inspect your cats/mufflers

 

[roswell998]

335 DPFE sensor voltage higher or lower than expected.
336 Exhaust backpressure high / PFE circuit voltage high.

Diagnostic Trouble Code (DTC) 335 indicates the Pressure Feedback EGR (PFE) / Differential Pressure Feedback EGR (DPFE) sensor is out of Self-Test range.

Possible causes are:
• Damaged PFE/DPFE sensor.
• Obstructed pressure inlet hose(s).
• Garage exhaust ventilation system affecting PFE/DPFE sensor operation.
PFE/DPFE system can sense a lack of pressure in the vehicle exhaust system. An efficient garage exhaust ventilation system that is installed during KOEO test mode may generate a DTC 335.
• Remove garage forced ventilation system and properly vent to atmosphere.
• Rerun KOEO test.

If you did in fact clean the EGR passages well then I would replace the mentioned sensor, or inspect your cats/mufflers

1. No gargage ventilation system involved.

2. I assume KOEO 335 test would not be affected by cats & mufflers since engine is not running.........correct?

 

[40BelowSummer]

the back pressure of the exhaust system, however i would try replacing that sensor if it is not much money

 

[roswell998]

I will remove and inspect the DPFE sensor later today.

Is the DPFE sensor something that can or perhaps might need cleaning or is it necessary to replace it?

 

[roswell998]

Another Question & Status Update

I removed DPFE sensor......hoses are like new

Sucked on both inlets to sensor and both hold vacuum......I assume there should have been some airflow...internal orfice probably stopped up.

Repost of earlier question:

Can brake cleaner or B12 be squirted into the vacuum fittings of sensor to clean it or do I need to replace with a new one?

 

[n8rsk8r]

hey bro

I think I have it, mine is the same, had to take the throttlebody off, remove the egr tube and clean the inltet that leads to the block, this gets clogged, it is not hard to do, just time, take pics to make sure all is cool, but you should be cool after that, the hole is only a couple mm thick at the point where it enters the block, I LOVE SHO's don't you! Seriously, I got to thinkin bout a high pow engine, and ours is awesome! I might try to make it bigger if I can when I redo bearings and lowerend. I will let you know how that comes out. Call Vadim, he will let you know the same thing!

Late

n8rsk8r

ps carb cleaner and something to unclog it!

 

[projectSHO89]

Another Question & Status Update

I removed DPFE sensor......hoses are like new

Sucked on both inlets to sensor and both hold vacuum......I assume there should have been some airflow...internal orfice probably stopped up.

Repost of earlier question:

Can brake cleaner or B12 be squirted into the vacuum fittings of sensor to clean it or do I need to replace with a new one?

The sensor is a DIFFERENTIAL sensor. It is intended to provide a DC voltage output that is proportional to the DIFFERENCE in pressure/vaccuum between the two test ports. There should be no airflow between the ports.

Replace the sensor.

Steve

 

[roswell998]

Replaced DPFE sensor as suggested.........So far nothing but 1's
Thanks for all the suggestions and help!!!!


Ashton