P0300 and P0171 codes 2014 Mazda CX-5

I took my 2014 Mazda CX-5 in to the local Mazda service dept bc I had a steady check engine light and an unusual surging idle while at stop lights. Before I took it in I swung by an O'Reilly's and had the code read which turned out to be a P0171. I had just changed the air filter so I checked the seal on that as well as my gas cap, but they were good.

The Mazda service dept just called me and said that they found a leak in my intake manifold and recommended fixing that and cleaning the injectors... For the cost of $475. They also told me that this isn't "the kind of thing your warranty will cover". I have an extended 100,000 mile warranty and am waiting for a call back about if this is covered now.

Just wondering if this all adds up... I thought a P0300 code (which means more than one cylinder is misfiring) would cause my check engine light to flash....it's also odd to me that this code didn't come up at the O'Reilly reading.

Thanks

You may still have 5-year / 60,000-mile factory powertrain warranty to cover your leaking intake manifold.

In the event its not covered under warranty (and if the problem was indeed a leaking intake manifold) a new one is PY01-13-100A about $250.00. If its the gaskets they should be around $20 or so each. https://www.amazon.com/dp/ (commissions earned) Did the dealer indicate the leak was at a gasket?

I would also read this: https://www.mazdas247.com/forum/sho...g-Intake-valves-CX-5-Skyactiv-Gasoline-engine

Also how old is your battery? An old battery may throw funky codes....hey everything is electronic these days who knows?

Reb

yrwei52 said:

You may still have 5-year / 60,000-mile factory powertrain warranty to cover your leaking intake manifold.

Click to expand...

I have a 10 yr / 100k mile warranty through United Car Care that the Mazda dealership sold me when I bought the car. They said the intake manifold repair wasn't covered.

The battery is a few months old.

According the Mazda workshop manual, P0300 is likely an ignition (spark plug) problem, and P0171 is likely a fueling issue, which also listed some contributors such as MAF sensor, fuel filter etc.. possibly having a fueling issue that is causing ignition problems. I'd check easy things first such as air filter and clean maf (easy).. sparks plugs are easy to check if you have the tool but if you are having fueling problems it'll happen again. Maybe put a fuel injector cleaner for two tank (if you tend to run the cheapest gas this could be an issue). PM me your email I can send you a copy of the WSM. You can find any pulled code in it and analyze it according to how the ecu in YOUR mazda determines these codes.

An intake leak isn't specifically listed on the P0300, but that's where it would come into play.. in which case you can run the engine and feel around listen for leaks..use a piece of paper or something..
I don't see how any intake leak is worth $450 unless they are replacing your entire intake manifold and charging labour to do it too.
An *exhaust* leak is one of the possible outcomes of the P0171 code, but the leak would have to be close to the engine, before the 02 sensor (which also is listed in the conditions as possibly being loose, which is highly unlikely)

Why are we discussing P0300 when you had a P0171?

An intake manifold leak is a possibility for P0171. Injector cleaning is a high profit item. If you can't fix the manifold pay for that and get 3 bottles of Red line SI-1 Fuel system cleaner and use it. It is the only in tank cleaner that works fast enough to detect it. You can even put 2 in the first tank full.

https://www.amazon.com/dp/ (commissions earned)

I'm no expert but the intake manifold is a non-moving part and I don't think the leak is on the manifold itself but rather a seal/s. They cost $15-20 each. The cause of the leak could be GDI related deposits compromising the seals?