P0174 existent after changing o2 sensor and brake booster line
 

I've had a p0174 for about 2 weeks now, I changed the brake booster vacuum line. Then yesterday I replaced the upstream bank 2 o2 sensor. Today the light came back with the same code also intermittent "cruise not avalible".

I have all new gaskets everywhere for my intake, new injectors, new fuel pressure regulator, new fuel filter, new plugs and coils, and no vacuum leaks from what I have seen(I'm going to double check). The only 2 things I can think of after looking around online is my maf sensor and the fact that longer then a month ago I was told my throttle body isn't closing all the way. However I'm inclined to dismiss the TB theory because I probably would have gotten a CEL up until recently.

So my question is where do I go from here? I'm leaning towards the maf sensor because it's affordable, however wouldn't I have a code for the other bank being lean? Since I only have the code for bank 2. My car runs perfectly fine, starts right up every morning. It seems like it hiccups sometimes when I enter onto the highway but that might be the car shifting and cutting me off in a way. Additionally is it ok for me to use the car like this? I need the car for school 5 days a week.

Have you checeked the IMT o-rings and the PCV hose? Those are the other two common sources of vacuum leaks. Also, dounble check that the ribbed accordian hose to teh throttle body is sealed well. If it was your MAF, there would be a code for that.

Did you replace all these part trying to fix 174 code?

@car5car no, these are just things I've done in the last 3k miles. I have done an upstream bank 2 o2 sensor and brake booster vacuum line since the problem has started though.

@alfa I have checked both of those and they show no sort of damage or tearing

Once again (can be found in SEARCH) =

Easiest way to check for vacuum leaks in the engine bay is start with a cold engine (will be apparent why). Start car and immediately spray the probable/possible vacuum leak areas with some starter fluid (hence cold engine). If there is a leak you will hear the engine change r.p.m.'s.

https://cimg7.ibsrv.net/gimg/www.jag...94f0f9dfc9.jpg

I have new imt o rings and a new line for the brake booster vacuum. My pcv hose is also the newer ribbed one. I have sprayed all 3 sections and no change in rpm

So although mine is the "other one", might be worth a try.

https://www.jaguarforums.com/forum/x...e-only-214539/

https://cimg1.ibsrv.net/gimg/www.jag...4fe0a3caba.jpg

If it was the MAF sensor wouldn't it be throwing a code that specifies the MAF, like P0101-P0103? Certainly doesn't hurt to change it out though, as it is so cheap and so easy to do.

@Alpha, you'd think so wouldn't you, but mine never did (other than when I forgot to plug it back in after cleaning it). Mine was as described in the thread. Been a while now and not once has it thrown the code again. I admit it's a bit strange.

Now if I could find the P0442 = Very small evap leak........another p.i.t.a.

MAF sensor came in today, going to pop it in when I get free time.

Will report back here if it solves my problem.

Thanks guys for the replies

Installed the MAF sensor and it's been over 50 miles and the light hasn't returned. The light was back by less then 50 miles when I put the o2 sensor in so i'm figuring I've fixed my problem.

Nice! Hope that is the case and the issue doesn't return.

well done :)

Another oddity, but if it works........