EEC-IV 335/332 Codes - any suggestions?

[Scott B.]

On my '93, I am getting engine codes 335 (Pressure Feedback EGR sensor or EGR Pressure Transducer - signal voltage higher or lower than expected) and 332 (Insufficient EGR flow detected).

I have the emissions manual, and am getting ready to read through it (many, many pages). Any thoughts or insite would be appreciated.

Has anyone had this problem before? If so, perhaps I could short-cut the diagnostic procedure (it is about 35 degrees outside!)

Thanks,

 

[MrShorty]

Be sure to follow the circuit test all the way through. Many times, people will replace the EGR valve itself to find out that the fault was actually in the DPFE sensor. Others find it's clogged hoses. Want to find the real problem and not start throwing parts at it.

 

[Scott B.]

I hope to run through the diagnostics today - the temperature will be in the upper 50's. Much more inducive to working on the truck.

However, last night, while driving home, the Check Engine light went out, and has not come back on. Even though the problem has gone away, I have either a partially clogged line, or an intermittent valve.

Let the fun begin....

 

[Albino 94LTD]

I have the same codes.

I remember seeing an episode of 'Two Guys Garage' where I think htey were working on these issues. I think I also remember there were several things they suggested be done besides simply replacing the valve.

Have you made any progress?

 

[Scott B.]

Update

The Check Engine has not come on for several days. (I have not re-installed my SuperChip, either.)

I read through the manual today, but did not start any of the testing. I hope to get to it this week.

Each test is pretty short, but I think getting to some of the components will be tricky.

Not looking forward to this....

 

[Albino 94LTD]

TV is good for something

I found the URL for the '2 guys garage' episode I was thinking about.

http://www.twoguysgarage.com/episodes/episode.php?epi=210

They took off the throttle body and cleaned both sides. If I remember the pictures, the back side had a lot of carbon and gunk.

I searched and found a lot of posts about the DPFE or EVPS going bad.((Differencial Pressure Feedback EGR) (EGR Valve Pressure Sensor) same thing), also about cleaning the IAC (Idle Air Control) ports which, on my 94 is within a couple of inches of EGR and DPFE.

I have ordered parts from Autozone Online. I intend to replace the EGR valve, DPFE, 2 vacuum hoses, clean the IAC and Throttle Body. I want to fix everything I can think of, the first time!

Total is about $110 with S&H. I have looked under the hood and all parts are very accessable. I already took the DPFE off to look at it. I have seen posts where people found cracks in the vacuum hoses but not mine.

Interesting note about your SuperChip. I have a Jet chip and K&N drop-in. I also had a 70mm MAS but my MPG has been pretty bad so I thought I would take it off and compare performance. It is too early to tell but I think my MPG is up. I just realized the CEL codes started IMMEDIATELY after taking off the big MAS. Coincidence? maybe. Time will tell.