2011 Mazda 3 1.6 P0171 fault code

[krazylegz]

Morning all,

The son has a 2011 Mazda 3 1.6 that has developed a P0171 fault code.

I can't see any obvious signs of vacuum pipes being split, however will take his airbox off and check under there on Wednesday when he is at mine.

Have had it on Forscan and got the following data, can anyone tell by looking at this before throwing money at it? Just don't want him to be buying 02 sensors and MAF's if it's not guaranteed to cure the problem.

Cheers

mazda fault code.jpg mazda fault codes 2.jpg

[ECU Doc]

I had the exact same problem with the exact same car of a customer.
It turned out to be a leaking intake manifold. Try to test it for any leaks, I hope to hear from you if its fixed, if not I'll try assist any further.

Do you have experience with testing a intake manifold on leaks? If not I can tell you how.

[krazylegz]

Thanks for your reply mate. He is coming up on Wednesday so will try it the old fashioned way with little squirts of easy start or similar whilst it’s running.

[ECU Doc]

Let me know how it goes, I´m actually curious if the problem will be fixed

[nbtechnic]

For Mazda specialists, do you know what is the specific tool for Mazda 3 year 2020, 1.8L skyactiv, automatic gearbox?
thank you

[Fibiana]

Не надо ничего снимать, подсосы воздуха решаются за пять минут дымогенератором. У форда-мазды есть проблемы с О2-БОШ, если они цикрониевые. Проверить просто, надо на ХХ обогатить смесь(шприцом впрыснуть топливо во впуск или обеднить) посмотреть реакцию сработки датчика кислорода.
А в итоге будет бензонасос или форсунки. Я их на стенде проливаю, давление топлива по манометру проверить не есть проблема. Но и есть вариант,что фазы распред вала убежали, там конус и звездочка на валу съезжает.
No need to remove anything, air leaks are solved in five minutes by a smoke generator. Ford Mazda has problems with O2 Bosch if they are zirconia. It’s easy to check, you need to enrich the mixture at XX (inject fuel into the intake or deplete it with a syringe) to see the response of the oxygen sensor.
And in the end it will be a fuel pump or injectors. I spill them at the stand, checking the fuel pressure on the pressure gauge is not a problem. But there is also an option that the phases of the camshaft have run away, there the cone and the sprocket on the shaft are moving out.
Мне трудно объяснять через переводчик, но если специалист будет возле авто, все поясню, куда и как посмотреть.

[nbtechnic]

@Fibiana, Thank you for this very useful mechanical information.

[krazylegz]

Hi mate sorry for the slow reply, yes you were correct it was the intake manifold gaskets leaking.

Diagnosed with a bit of easy start whilst the engine was running, so ordered the gaskets. Went to do the repair and one of the bolts was severely rusted so ordered some new bolts and done at the weekend, all is well now