I have a stock (200K miles, original exhaust, motor, etc.) 1996 Cobra. Running OK, but now throwing codes related to the smog pump (P0411, "Secondary Air Injection System Flow Improper") and one of the HO2 sensors (P0153, "Upstream Heated Oxygen Sensor circuit Slow Response - Bank No. 2"). The problem seems identical to this older SVT thread (don't know how that one was resolved, possibly by new O2 sensors).
I've removed the AIR motor, tested it on battery, appears to spin up fine. Checked all vacuum lines, fixed some that were bad (on evap emission canister). Checked downstream connection of AIR hoses to the so-called Thermactor AIR Diverter Bypass Valves (one per header bank, air and vac connections on these seem OK). Reassembled all, motor still throwing a code (now P1414, "Secondary Air injection monitor circuit high output"), which occurred almost immediately after a cold start. Motor surges on low speed deceleration, and holds a very fast idle (~1700 rpm) at closed throttle or after coming to a stop (eventually settles after ~1 minute).
Two questions:
1. Can anyone explain how the SAI pump works with the air input (the short J-hose) actually plugged with a plastic cap (attached image from ebay, but mine's identical) -- how can this work?
2. Given that the pump seems to be nominally functional (at least it spins when directly connected to 12V battery), what other component(s) would prevent the SAI system from working correctly (given the above)?
Should I just replace the pump anyway? (Sorry, 3 questions).
Thanks much in advance for any ideas.
I've removed the AIR motor, tested it on battery, appears to spin up fine. Checked all vacuum lines, fixed some that were bad (on evap emission canister). Checked downstream connection of AIR hoses to the so-called Thermactor AIR Diverter Bypass Valves (one per header bank, air and vac connections on these seem OK). Reassembled all, motor still throwing a code (now P1414, "Secondary Air injection monitor circuit high output"), which occurred almost immediately after a cold start. Motor surges on low speed deceleration, and holds a very fast idle (~1700 rpm) at closed throttle or after coming to a stop (eventually settles after ~1 minute).
Two questions:
1. Can anyone explain how the SAI pump works with the air input (the short J-hose) actually plugged with a plastic cap (attached image from ebay, but mine's identical) -- how can this work?
2. Given that the pump seems to be nominally functional (at least it spins when directly connected to 12V battery), what other component(s) would prevent the SAI system from working correctly (given the above)?
Should I just replace the pump anyway? (Sorry, 3 questions).
Thanks much in advance for any ideas.