P0171 & P0174 Scan Codes

I thought this problem had been solved but scanned again today and getting P0171 and P0174 codes on the scanner. A couple of months ago I changed the K&N induction kit the car came with when I bought it back to the standard air box and filter. Today I checked and all the jubilee clips look tight and I can't see any obvious leaks. One area I noticed last time was the Allen like bolts holding the MAF sensor was a bit loose so tightened them (does this part need a gasket). The car definitely felt more sluggish today and didn't want to pull as strongly as the last few weeks. Is there more I should be checking before I take this any further....ideally if there's a video or list of how to check these things out that would be great.

If your scanner can read some actual values then you need to look at the maf voltage ign on but engine not running .. ideally it needs to be at or very close to 1.0 volt . This will say if its a maf fault .. other items are listed below .. oil cap loose is not uncommon shall we say .

I was going to say test the maf but it could be a vacuum leak. Demort will know much more than me but id say faulty maf being both banks or get a smoke test done to check for vacuum leaks would be next. if you disconnect the maf do the codes change at all?

I will see if I can get more information out of the scanner and let you know what it says.

I don't normally respond to what others post on a thread as i talk to the Op direct and tend to leave it at that .. All i want to add is that this is a long term fault code .. if you clear the codes then it wont come back for about 4-5 days if it is an actual fault . Basically the car monitors emission related items over several warm up cycles before it determines there is a fault . Clear the codes .. unplug the maf and you will only get a maf fault due to the above .. that would logically lead you to assume its a maf sensor fault . It will not be an accurate test if looking for a repeat of the original codes basically . A live value of the maf readings will prove it .. 1.0 volt with ign on or approx 18 kg/h with it running .. about 1.35 volts . No offence meant as this may well be a maf sensor fault but there are other things that can cause it so they all need checking

Fair point demort. My thinking re removing the maf was if new codes were thrown up or the engine note changed that could lead it to being a different issue as the sensor is obviously giving readings. Didn't know about the cycles etc.

Thanks guys as soon as I get a chance will report back. Just been doing some research in case I do need a new MAF sensor how come there's such a huge difference in prices for what looks basically the same sensor? I've seen about £16 to £198 for them.....is there any recommendations on what to buy if I do need one?

Looking at some photos earlier I did notice this on the air box.....should there be something attached to this part?

Not sure what or where that is on the airbox as I don't have one I can remember. have you got a wider shot? If it's the airbox it's job is to get air in and clean it to send it to the engine so not sure it would cause a vacuum leak but could be too much air bypassing or flooding the maf. I will leave this one to Demort as I will just be guessing.

Hopefully you can see where it is on the air box from this photo.

Seeing it now it should be where a clip to hold the maf wire steady sits so I don't think it's a hole all the way through. Found this pic on Google for reference for you.

Thanks that makes sense....another thing off the list of worries

Kbald is perfectly correct .. it's a clip fixing . I also regret my previous post .. i get frustrated at times .. a simple fault code read out and a look at actual values by an Indy will often point you in the right direction .. We are not bad guys .. hopefully we all still try to offer a service and as such a £30 read out and and explanation of what we feel is the problem will help .. you can do what you want with that info being it ask us to continue diagnosing or replace the item on an educated guess from someone like me . At the end of the day that's often how i fix cars .. i can't always prove an item is at fault .. i have to make a judgement , that then is on my head . Sometimes i don't like what i post .. but i try to give the best info i can .

You keep on posting whatever you like ....its a goldmine of information for us amateurs. Hopefully tomorrow I may get sometime to have another look at it.

Here's the first scan