2008 Tundra secondary air options and intermittent p0300

I have some codes for the secondary air check valves. The pictures of the scanner are what I’m getting after a few drive cycles. The dealer printout is what was on the truck when last owner had it in the dealer for diagnosis last spring.

The pump is newer, as it was replaced by previous owner last year. Has anyone had any luck with the gen 1 Hewitt kit? I seems like it would work for me. The gen 2 is out of my budget given shipping and conversion to Canadian Loonies. It be cheaper to just replace the valves in that case.

All I have done so far to correct it is try and clean connectors up, but no change.

The truck is 2008 4.7
207,000km (130k miles)

PS you can see I also have a misfire code. This happens briefly under very specific load. I haven’t dug into this yet but am staring with new plugs and cleaning all engine bay grounds. (P0300 always when it happens, individual codes are combinations of 304, 305, 307, 308)

For some background, I am not a mechanic but an intermediate/expert parts-changer. I can do most jobs right up to motor/trans swaps but only with instructions.

Also, unlike many new users. I promise to post the fix to this thread so all the forum users (and google searchers) can benefit.

 

I know no one replied to this thread, but for the sake of the searchers and the googlers, here’s what happened.

replaced both secondary air valves. I found it strange that both would be bad at once, but even after using a tech stream knock-off to follow the testing procedure for the bakers they came back as dead. This got rid of the secondary air codes.

as for the misfire, it was the spark plugs or possibly a bad ground on engine. I replaced the plugs with denso replacements and cleaned all engine grounds at the same time. No CEL since.