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p0491

M

MavWreck

New member
My check engine light popped on the other day and the code it's showing is p0491: Secondary Air Injection System Insufficient Flow Bank 1. The thing is, I'm fairly certain that I do not have SAI as there is a a large empty space at that location in the engine bay.

I'm by no means an expert so is there another location (other than in front of the fuse box) that an SAI would be lurking or is this code being thrown as a result of another issue; maybe a bad sensor?

Thanks
 
M

MLue1

Drag Racing Champion
MavWreck said:
My check engine light popped on the other day and the code it's showing is p0491: Secondary Air Injection System Insufficient Flow Bank 1. The thing is, I'm fairly certain that I do not have SAI as there is a a large empty space at that location in the engine bay.

I'm by no means an expert so is there another location (other than in front of the fuse box) that an SAI would be lurking or is this code being thrown as a result of another issue; maybe a bad sensor?

Thanks
Click to expand...
If you don't have a SAI pump then it could be a false code, use a OBD Reader to reset the error code and see if it comes back.

BTW How is your battery doing, when batteries get old or when your alternator is on the edge there are more instances of false codes.

That's my 2 cents


EDIT: Love your User Name :lol: :thumbsup:
 
W

Wascally Wabbit1

Drag Racing Champion
Whine or vacume kind of noise? Mine is pretty loud after the intake but it shouldn't whine. That is a sign the pump is going south. I have read there have been issues with the rivets that hold the pump together coming apart.
 
FlowMK6

FlowMK6

Ready to race!
MavWreck said:
https://drive.google.com/open?id=0B3wKdgAYAmtWRGZURkNNNmhJQ0VnVWlGSjRzU2w0bkVwaURr

This one here? I checked the hose for cracks and didn't see any. I did a cold start and it appeared to kick in with a very high pitched whine for a few seconds.
Click to expand...

Yep this one, you should have another similar hose but a little bit smaller (I don't have one on my cars, but from what I remind the PCV breather hose is smaller that the SAI hose)

If you hear the SAI pump, then it's probably not a fuse or relay, it could be a leak, the combination valve or maybe the pump isn't good enough, I don't know how the combination valve is managed on our engine, if it's vacuum controlled or not... If the combination valve is controlled by a vacuum, it could be possible that you have a vacuum leak on that line so the combination valve doesn't work as it should.

For finding leak, you should use an EVAP tester. If you find any vacuum line on the combination valve, I would use a vacuum / pressure pump to test the SAI solenoid and the lines at the same time
 
pdan

pdan

Ready to race!
Wow I can’t believe this popped up. Just had this issue yesterday and today. Posted in the Stratified thread as well. I’m CFBA I’ve been reading through a few older threads on here. It seems to be an issue with the secondary air injection system. I’ve got a Unitronic intake with the second filter. I’m guessing something got pinched or maybe missed when my intake was taken out or put back in? Going to try and figure out if everything was put back together correctly today. But when I did load my new tune today on first start up I heard a biblical screeching noise for the first 2 seconds. So maybe the pumps dying?



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pdan

pdan

Ready to race!
Figured I’d post this in here as well in case hasn’t checked this yet. Well sometimes it might be the simplest things. I hope it is this time ha. I went digging around and found that the hose that leads off my SAI was not connected to whatever hose this was. I started it up and felt a massive vacuum when I put my hand over it. Sure enough I went back in and had the code again. Attached it back, cleared the code and my idle seems to be back around 1.05. Hoping it stays that way. A little difficult to see.









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M

MavWreck

New member
pdan said:
Figured I’d post this in here as well in case hasn’t checked this yet. Well sometimes it might be the simplest things. I hope it is this time ha. I went digging around and found that the hose that leads off my SAI was not connected to whatever hose this was.

Sent from my iPhone using Tapatalk
Click to expand...

I checked all the connections after seeing this and they appear to be solid. Sigh. Well, it was worth a try.
 
W

Wascally Wabbit1

Drag Racing Champion
Have you gotten a look down at the actual pump to see if it is cracked of coming apart. In another note there is a way to delete the pump if it is bad as they are expensive to replace. Not exactly environmentally friendly tho.
 
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