ringo234

When I gun my engine (in neutral), it will pop, pop, pop (backfire). I was told my diverter valve was bad. I found out where it is but still understand its purpose.

Thanks for any replies.

TPI

Well, to my knowledge it simply channels the excess
exhaust gases from the exhaust manifolds/EGR compliant
hedders & re-routes the dirty gases down to the catalyct
converter to be burnt off at tempurature or cycled back
through the combustion process.

I am failing to understand why a bad diverter valve would
cause obnoxious popping as you mentioned. Unless the unit
is seized altogether, but again.. popping is not what I imagine
it doing if its failed.

Does the car pop with it removed? how about the smog
pump down below fitted on your accessory bracket? If that
is toast.. then, I could imagine noise comming from that.


Hope that helps

TPeye

The diverter valve controls where the air from the AIR pump is sent. When the engine is cold the air is sent to the exhaust manifolds. When the engine is warm air is sent to the catalytic converter. When the you floor it or let off the gas, the air is diverted right back out, it is not sent to the cat or manifolds.
Why are you flooring it in neutral? You may just be hitting a rev limiter or over revving the engine. Where is this popping coming from?

ringo234

I don’t usually, but a friend wanted to hear my new exhaust system. It sounded like it was coming from the exhaust.

TPI

Thanks for the clarification,

I for dont believe it could be your diverter valve producing
that noise. Id be shocked if it was. Its hard to really tell
what you have going over there, it could be as simply as
what TPeye stated.

Your best bet is to turn the car on, have somebody
accelerate it untill the noise occurs, and you try to locate
it from underhood/underneath.

Good luck

87IROCZ350TPI

When is the popping present? Is it actually while you are flooring it, or is it when you let go of the gas after flooring it. I've heard of popping while the engine itself is decelerating.