CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

EGR code? ‘93 F250

So, I fixed the starting issue but my cycle never seems to end. While taking a short drive the truck threw a check engine light.

Went home and hooked up the OBD1 Code reader. 332: Insufficient EGR Flow Detected.
That was only with KOEO (key on engine off). KOER (key on engine running) gave me 111 which is all clear.

Why would it show with the engine off and not on? What damage can and could this have caused?

Also, Im aware of the replacement parts and that its typically a vacuum leak, but how do i test this?

Your Ford has the Delta Pressure Feedback EGR system.

This means a differential pressure is measured at an orifice between ports 1 and 2 at the EGR tube, and measured by the DPFE sensor which determines if threre’s enough EGR flow.

Sometimes this orifice gets plugged the carbon which causes a restriction of flow and causes this code.

Then this carbon breaks loose and flow is restored and the code is set in memory.

The purpose of the EGR system is to introduce a small of inert gas into the combustion process to reduce NOx emissions.

What I would try first is disconnect the negative battery cable for ten seconds to erase the code and see if it comes back.

Tester

I will try that, thank you.

So basically, if I lose the EGR system due to a block, I’ll basically fail emissions? What damage do I risk doing to the motor the longer this goes unfixed? Assuming the code comes back.

As it stands if it doesn’t hurt the truck then itll fall low on the priority list of to do’s. Im not in an emissions area, and the one county that does, only checks for the 02 sensor codes. If it doesn’t have them you are golden.

Without the EGR system operating correctly, the combustion temperatures will be hotter.

I’ve never seen an engine damaged from inoperative EGR system.

There was once a time when engines didn’t have EGR systems.

Tester

So basically as long as my coolant system is working along with the 02 sensor im basically in the clear but it should eventually be done…

Yeah.

If there’s no pinging from the engine, it can wait.

Tester

Nope. Just the good ol’ exhaust leak.

Only thing I noticed was a higher pitched noise from the engine. Idk where but I probably have a vacuum leak somewhere.

Itll get done, probably when the next oil change comes around…