454 Vortec help

[Greg36]

I have a 454 Vortec and it was throwing a code P0401 “Exhaust gas recirculation flow insufficient” and P0410 Secondary air injection system” I clean the EGR valve and made sure the EGR port wasn’t clogged with carbon... did not solve my problem. The u threw a new EGR on to make sure. Wasn’t it. then I Replace the map sensor because I thought I damaged it when I cleaning my throttlebody and now my truck runs like crap doesn’t idle right and is still throwing the P0401 and P0410 codes and now with an additional running lean codes p0171 and p0174. Any lnoledge would be greatly appreciated thank you

 

[PlayingWithTBI]

Put a scanner on it and see what your O2 sensor(s) is(are) doing as well as your other sensor inputs (TPS, CTS, MAP, etc. Don't need to throw more parts at it until you know which ones to throw. Also check you vacuum lines and ground connections.

 

[ZRoe]

I'm guessing your truck has California emissions AIR pump on it?
That pump and the associated check valve could be going bad and if the 02s don't see the extra air that pump normally provides it would throw off the fuel trim as well.

Sent from my moto e5 supra using Tapatalk

 

[Greg36]

Thanks for the replies guys I put my old master flow sensor back on and the truck runs OK again now I’m only throwing the code P0410 for secondary air injection System?

 

[ZRoe]

I can't remember the exact code I had but on my 97 with the AIR pump there was a relay for the clutch on the pump and it got unplugged by accident one time and started throwing an AIR system code. Presumably the ECU noticed the lack of fresh air in the exhaust during start up.
The relay was in the under hood fuse block where the AC relay is at.
Best of luck to you

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[andy396]

You must be registered for see images attach

 

[andy396]

The rest can be found here in Vol 4 for a ‘98, pg 6-2909

88-95 Service Manuals
https://r.tapatalk.com/shareLink?sh...ads/88-95-Service-Manuals.43575/&share_type=t

 

[Schurkey]

So the computer monitors the O2 sensor(s) for confirmation that the AIR system is working.

Therefore, a failure in the AIR system, or a failure in the O2 system could set an AIR code.

 

[Frogprince]

I unplugged my Air Pump and I haven't gotten the check engine light. I had to unplug it due to a growling bearing and since they 454 Pump is no longer in stock anywhere good luck finding one.

I was going to remove mine but the belt routing was different. I was going to purchase an alternator bracket from one without the pump and swap over. Just haven't got the bracket yet nor the time to tear it down.