OK. I've been reading a lot. Now it's time to ask.
I have a 91 Suburban 350.
I had a nasty off idle stumble and disconnected the EGR vac line. The stumble went away and I've been driving it that way for a couple weeks.
One obvious issue was the fact that the entire exhaust system needed replacement. A new Y-pipe, 3 new studs to connect to manifold, Magnaflow muffler, and I kept the cat since it was still clean and I was running out of $ quick.
I drove it 30 miles on the highway today to see if any codes would come up. Codes are:
13. Oxygen sensor signal stays lean during warm engine cruise, your O2 sensor could be unplugged or faulty wire. (This tells me the ECM knows the engine is warm-eliminates CTS?)
32. Fault in exhaust gas recirculation valve diagnostic switch (known because the vac line is plugged)
44. Oxygen sensor lean (Exhasut work done-need to check)
I have a new EGR valve( ready to go in because I thought I had it isolated by disconnecting the vac line. Code 32 makes sense because the vac line is plugged. It got too dark to check the wiring to the O2 sensor, but I'm thinking either the wiring got buggered when the new studs were put in or the non leaking pipes exposed a problem.
My plan: check O2 wiring for obvious problems, replace O2 sensor (if the condition of the rest of the system is an indicator, it's probably due), TBI rebuild kit ($25 and a little time is probably worth it anyway), replace any suspect vac lines. Install new EGR valve?
Any insight is appreciated.
I have a 91 Suburban 350.
I had a nasty off idle stumble and disconnected the EGR vac line. The stumble went away and I've been driving it that way for a couple weeks.
One obvious issue was the fact that the entire exhaust system needed replacement. A new Y-pipe, 3 new studs to connect to manifold, Magnaflow muffler, and I kept the cat since it was still clean and I was running out of $ quick.
I drove it 30 miles on the highway today to see if any codes would come up. Codes are:
13. Oxygen sensor signal stays lean during warm engine cruise, your O2 sensor could be unplugged or faulty wire. (This tells me the ECM knows the engine is warm-eliminates CTS?)
32. Fault in exhaust gas recirculation valve diagnostic switch (known because the vac line is plugged)
44. Oxygen sensor lean (Exhasut work done-need to check)
I have a new EGR valve( ready to go in because I thought I had it isolated by disconnecting the vac line. Code 32 makes sense because the vac line is plugged. It got too dark to check the wiring to the O2 sensor, but I'm thinking either the wiring got buggered when the new studs were put in or the non leaking pipes exposed a problem.
My plan: check O2 wiring for obvious problems, replace O2 sensor (if the condition of the rest of the system is an indicator, it's probably due), TBI rebuild kit ($25 and a little time is probably worth it anyway), replace any suspect vac lines. Install new EGR valve?
Any insight is appreciated.
