Thread: Failed emissions.

Hi. I have a 96f150, dual tanks, 4x4, I-6. Ok so I just failed emissions. And they gave me these 4 reasons. Im lost and if anyone can help i would love it. Reason 1. P0411 "SECONDARY AIR INJECTION SYSTEM INCORRECT FLOW DETECTED. Reason 2. P0401 EXHAUST GAS RECIRCULATION FLOW INSUFFICIENT DETECTED. Reason 3. P0171 SYSTEM TOO LEAN (BANK 1)(2). Reason 4. P0174 SYSTEM TOO LEAN (BANK 2).

Originally Posted by Raptor05121

1 & 2 have to do with the EGR valve and the last two are vacuum leaks, very common

Meaning you're probably going to have to replace your EGR (Exhaust gas recirculation) valve, and either the PCV or a vacuum line. Try and find the leak first though.

I through a too lean code a few weeks ago and it turned out to b my gas cap. 3$ and a gas cap later..... Cleared code. And it is fine now. But egr and vacuum leaks r common as the professor stated and resident funny man

Originally Posted by Joe Grasso

I through a too lean code a few weeks ago and it turned out to b my gas cap. 3$ and a gas cap later..... Cleared code. And it is fine now. But egr and vacuum leaks r common as the professor stated and resident funny man

Ok. Thank you. I did fix a few of the issues , but when I just ran it through again the check engine light didn't come on when started. I did nothing at all that would have caused that. So they won't pass it now because that light won't come on. Any idea why it would suddenly stop working?

Originally Posted by Golden

Ok. Thank you. I did fix a few of the issues , but when I just ran it through again the check engine light didn't come on when started. I did nothing at all that would have caused that. So they won't pass it now because that light won't come on. Any idea why it would suddenly stop working?

The check engine light isn't on while it's running? Then you have no issues lol jk. Scan it again and make sure all the previous codes are cleared. That way it'll reset and be able to detect if there is still an issue that needs to be fixed. What ones did you fix so far?

Burned out bulb? Just a guess...

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Does it not come on when you turn key on?

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Originally Posted by lee reece

Burned out bulb? Just a guess...

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Does it not come on when you turn key on?

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No it doesn't come on when I turn the key on. It worked on my first test w/emissions which was only two days prior. All I did as far as repairs between tests was I fixed some vac leaks and got a new gas cap. I did nothing at all to any electrical things. I have a hard time believing the idiot light blew in between the retest. Could the first guy who tested it accidentally done something to the datalink or ecu? I'm pretty lost on this one.

Sounds like a burnt bulb, I had an escort that failed over a burnt bulb

It should come on when you first turn the key on to start for 2-3 sec and go out. This is a systems check every time the key is on. The bulb is burnt or fuse blown.

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Originally Posted by lee reece

It should come on when you first turn the key on to start for 2-3 sec and go out. This is a systems check every time the key is on. The bulb is burnt or fuse blown.

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Some power failure of some kind .

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