Corolla t sport running issuea

[Wayne80]

I have just brought a 2003 t sport 65000 miles and believe not been lloked after well . I have had runnjng issues the engine holds back and shakes harshly from about 15mph upwards and dosent stop till u let off the throttle and it has loss of power with it . Its fine on tick over dosent cut out starts all the time . I have replaced plugs , coils , maf , air filter , new exhaist system nd lambdas but stilm tje same im at a loss any help please 

[SanaYusuf]

Any codes? EML on?

[Wayne80]

Only code that came up today is p0171 but nothing else . Eml light only comes on if i try to take the revs up past 6000 guessing something to do with lift bolts 

[SanaYusuf]

2 hours ago, Wayne80 said:

Only code that came up today is p0171 but nothing else . Eml light only comes on if i try to take the revs up past 6000 guessing something to do with lift bolts 

So it doesn't go into lift then? Any idea what p0171 relates to? 

I was gonna say lift ocv filter which is behind the oil pump on the side of the head and vvti ocv filter which is behind the alternator could be your issue, both need to be removed and cleaned.

(I've just researched that code briefly and it's relates running lean. You might have a vac or air leak.)

[Wayne80]

Yeah was going to remove and clean the ocv filters just had a engine flush and change . I was thinking a vac prob due to the person before has messed aroud with all the vac pipes and i cant find a proper diagrham of how they all go 

[Wayne80]

Oh sorry and no dosent go into lift but very sluggish trying to get to lift anyway 

[SanaYusuf]

3 hours ago, Wayne80 said:

Yeah was going to remove and clean the ocv filters just had a engine flush and change . I was thinking a vac prob due to the person before has messed aroud with all the vac pipes and i cant find a proper diagrham of how they all go 

Ah well that might well be related to the code you have, some un-metered air getting into the engine. Can you post up some pics of your vac lines, maybe we can help?! Do you have a induction kit?  as if not fitted correctly can cause issues.

[Wayne80]

No its standard but i believe they did at one point have an induction kit on 

[SanaYusuf]

Hi mate, yes something doesn't look right with your vac hoses around your air box but I'm not sure what as I removed mine as I installed a induction kit. 

There is a vac hose that comes from the back of the air box, it controls the flap on the back of the air box. Can you tell me where that goes on your car?

[SanaYusuf]

https://www.knfilters.com/instructions/69-8751_inst.pdf

These are instructions for fitting a k and n induction kit, maybe you can work backwards to work out what goes where.

[Wayne80]

Hi my air box hose runs to a splitter that joins the switch valve and the manifold .

[Wayne80]

Car runs fine but has a slight misfire on idle and dosent seem to have all the power as normal ... still get eml light when trying to hit lift even thou all lift bolts have been changed 

[SanaYusuf]

7 hours ago, Wayne80 said:

Hi my air box hose runs to a splitter that joins the switch valve and the manifold .

Doesn't look right at all, that blue plastic piece should be inline between intake manifold and that connecting t-piece as in my pic.

[SanaYusuf]

Also what connected to this on the back of your air box? I'm pointing to it in pic.

[SanaYusuf]

I've been having a look at engine bay pics on google aswell as playing around with my air box and I think you should try this set up

*vac hoses not attached properly.

[Wayne80]

Hi The connector coming from the air box hasnt got anything on it . Do you know whats ment to go on that at all ? 

[SanaYusuf]

I'm not 100% about the way those vac line are set up, best I can do considering its not installed in the car.

Also I remember when installing my induction kit I disconnected pipes that go to that blue valve on the back of the air box and that caused me exact same symptoms as you are having so check that valve and it's connections.

When you replaced the MAF sensor was it with a new/genuine one? Second hand sensors can often be dirty/defective and personally I'd only replace with a new one from Toyota.

From the fault code you mentioned earlier in the thread you have a vac leak somewhere and from research it could be the gasket that goes between the intake manifold and the head, it deteriorates and lets in unmetered air, seems that was a common issue a few years ago.

Sorry I couldn't be more help🤔

[SanaYusuf]

2 minutes ago, Wayne80 said:

Hi The connector coming from the air box hasnt got anything on it . Do you know whats ment to go on that at all ? 

Which one?

[Wayne80]

The one you are pointing at on back of air box 

[Wayne80]

No thank you its been very helpful all parts are new parts not toyota but of good oe quality not cheap parts 

[SanaYusuf]

20 minutes ago, Wayne80 said:

The one you are pointing at on back of air box