Hi folks,
So got a rebuilt motor put in my 89 4wd truck, 22re motor. No check engine light (CEL) issues before. Now it lights up the CEL with 7 1 code after few miles of driving every time. I put a new EGR Valve, new Vacuum Modulator, new EGR temp sensor and replaced the vacuum switching valve, still same issue. EGR is working, as verified by smooth idle from cold and checked by local Toyota shop. The egr cooling plate was cleaned when motor was swapped. Old egr was plugged but for some reason CEL didn't light up then. Yes, a 10 ohm resistor is my last resort, but it seems this problem has happened to others, any advice/suggestions for me? Vacuum lines have been checked for correct routing. Appreciate it!