Bee Tee

98 z71 5.7 threw the p410 code today CEL is on. The scanner says there's an issue with the sendondary air injection pump. Where the heck is it? Getting a bit of a rough idle but drivability seems fine. Checked for vac leaks and loose or broken connections. None that I could find. Can some point me in the right direction so I can fix this issue. Can't find anything regarding this issue with a 98 z71 online. Help.

Gumby22

The air pumps are typically mounted on right (passenger) side of the engine, but the pump itself isn’t typically the cause of this code.

The PCM relies on O2 sensor readings to detect whether or not the AIR system is functioning.

First check the AUX-B fuse in the under hood fuse block. If good, swap the AIR injection relay with another relay (such as the horn) to see if it’s working.

Bee Tee

I don't have an air pump under the hood nor is there a relay for it in the relay box. There isn't even pins in the box for a relay in that location. Is this common? I did a scan and the o2 sensors where within range, fluctuation between 100 and 900 mV but never gets steady as I was told it was supposed to. Also getting low voltage at cat code.Mabey I'll change the o2 sensors and mabey replace cats what would you do?

Gumby22

Ignore the code. Without the air pump or relay pins, someone either deleted the system or they swapped in a PCM from a truck that did have air injection and the code is setting because it wasn’t programmed correctly.

This could actually explain the connector you asked about in your other post - it may have been for the AIR pump. During manufacturing of these trucks, GM identified emissions connectors with red.

I can’t see any details in that pic, but is a bypass pulley installed on the right side of the engine?

Bee Tee

Just checked and the PCM is in fact swapped as theres a local junk yard tag on it. I think you just solved my problem. Going to get a new ecu and update. Will upload more pics as well. Thanks a ton.