Misfire due to "bad gass"

Go to the local mechanic, he going to give you the necessary answer

Posted via the PriusChat mobile app.

 

Go to another place that knows about egr circuits

 

How many miles on it?

A new intake isn't going to do anything. As far as I know it's rerouting the EGR (Exhaust Gas Recirculation) passages a little. If you're miles are getting up the EGR's likely clogging, all the way from the exhaust connection.

The intake manifold is the last leg of the EGR circuit, and if the miles are high it's likely got clogged passages. Cleaning will fix that. It's something that needs to be done maybe every 100K miles. And the whole EGR circuit.

Maybe try a leak-down test first.

Another good first step: remove and check the condition of the EGR pipe, the stainless steel tube between EGR valve and intake manifold. This'll give you some idea about the rest of it.

 

If it was a misfire, what Are the codes?

 

Have you tried removing the spark plugs and checking it? Swap the ignition coils and checked that?

One cylinder misfire wouldn’t be considered “bad gas” as it’ll affect all of the cylinders. Intake manifold wouldn’t cause one cylinder to misfire either... and I haven’t heard of one causing it.

 

Where did you pump your gas at?

 

They recommend the new intake manifold because of the attached TSB, dated November 2015, which was the end of the line for Gen 3s. There are five different versions, so they Toyota kept thinking that the updates would solve the problem or help, and apparently think the last version works best.

Alternatively, any of them will work, though probably not as well as the last revision, if you clean and clear out the clogged up passageways. The dealer will not do this because replacing is faster than cleaning, and time is money. You can clean the existing intake manifold yourself with pipe cleaners and solvent. The rest of the EGR system also needs cleaning.

 

My purely speculative guess is that when you say the dealership has a 2 week back-order on intake manifolds, that when you appeared with your symptoms they were HOPING the simplest solution would work, to avoid adding your name to the list of customers waiting.
So they tried the "Bad Gas" and fuel system cleaner route. Maybe more just to buy themselves some time.

But if you have an alternate mechanic you trust? You probably don't have anything to lose having him look at it. But I kind of suspect you might need the manifold.

 

I’ve never tried Exxon, so can’t say if it’s bad.

Are they replacing your intake manifold for free since it is a TSB?