Code 51 ?!

[fixkick]

1994 Sidekick JLX. 4 door, 4 wd, auto, 16V, Federal car (not california). Code 51 popped on, right after I filled. up with gas.. car sounded a tad funny too. Says EGR system faulire. usually on California cars.. ok.. Any ideas on what this could mean?

Doing some research.. the EGR is stamped K5T542 - which I see is a California emissions equipped EGR. Plus it has the EGT sensor. So maybe my hood was changed? Or maybe because the car was sent and spent most of its time in Washington state? Anyways, I need to figure this out, please help.

the cars hood clearly shows a FEDERAL Car, not CALIF,
the calif egr has 2 wire sensor that fits into a 2 wire, harness plug that only calif car with calif harness can fit. this sensor is just thermistor thermal probe.
the calif egr main works ok on FED car but not the reverses, in the CALIF EGR main valve in a FED car the 2 wires go NOWHERE (dangles)<<< not a problem that.
the Ecu is also a CALIF. or a FEDERAL ECU. (model number on top tell this. )

51 means the EGR system is failing, for vast reasons. (complex)
EGR test fail,  

IS the cards CAT missing TWC three way cat? (missing or rod'ed out, gut of it missing)
the first test it the index finger stall test. (and makes sure it does not stick open)

at idle push this ring plate below and engine drops to 400 RPM or stalls. this proves 2 things, valve is not stuck closed, and the EGR path (exhaust) is not fully clogged.
video ( this guy uses vacuum hand tool at vacuum nipple (not bark) and the valve opens and here it nearly stall. below.

https://www.youtube.com/watch?v=UPO7B7yH43w






my gen2 EGR page his here, it s scary all the things that can fail here.
no missing cart,
not wrong ECU
the FED car uses vacuum tests (via map sensor vacuum DROP test ) to see if EGR works, if not code 51
the Calif car (and cal ECU) uses the egrt sensor on the side of above egr main to see it get super hot as EGR opens. if not 51 code.


the gen 2 page is here.

https://fixkick.com/EGR-Gen2a.html