97 318I fault codes- p1174 and p0442

[BMWCOLLECTION]

Hi!
I helped my brother replace the engine on his 97 318I (he blew up the original one). The engine runs well, he's been driving it for almost a year now, commutes about 60 miles a day to and from work. However, check engine/service engine soon light is on with fault codes: P1174 and P0442.
I've replaced the intake boot (from air mass sensor to throttle body) for it being torn and replaced the gas cap. Codes returned within 50 miles of driving it.
I've tried spraying brake cleaner on whatever breather hoses, vacuum lines, and intake parts that I'm able to with the engine running and found no significant difference on the idle (can't find air leak).
I tried building a home-made smoke machine and can't find and leaks with it either (not sure how great the smoke tool actually works though or if I'm running the test properly). I tried blowing the smoke into intake system through the intake boot that I've replaced and blowing smoke through the purge valve hose leading to the tank.
I'm open to any suggestions!

Thanks in advance.

[Eric93se]

The charcoal canister is under the spare tire, check for broken nipples and such. Also above the rear right tire is a capture system that also gets a broken nipple on some. To drop down the canister behind the gas cap you have to disconnect the fillter tube, it's not difficult, there are two 10mm nuts, one high up and the other further down the filler. The rubber that surrounds the very top of the gas cap/filler pulls out with little effort.

- - - Updated - - -

http://www.realoem.com/bmw/enUS/part...BMW-318i&mg=16

[BMWCOLLECTION]

I did check the charcoal canister and found it and the connections OK, it's not bad accessing it, I'll expose it again and shoot some pictures of it so you can see, not before I check out the capture system that you're talking about located above the rear right tire. I looked at the parts diagram you provided the link, just to verify: you're talking about part # 16111183107, correct?
I'll see my brother and his car again in two weeks. I'll check back in with you then. Thank you for your time.

16111183107

[Eric93se]

This expansion tank

http://www.realoem.com/bmw/enUS/show...diagId=16_0214

[BMWCOLLECTION]

I'll check it out and touch base with you next weekend. Thanks again.

[BMWCOLLECTION]

Sorry for the late follow up, just this weekend is when I was able to meet up with my bro again. I checked out the expansion tank and rechecked the carbon canister and both units and their attaching line connections are intact (see attached images).
On the bright side: I read the fault memory and found that fault P0442 didn't return since I last cleared it; during my last inspection, when I was attempting to test the EVAP system for any leaks, I disconnected the purge valve to inject smoke into the line going back to the fuel tank using my home made smoke machine, even though I didn't find a leak, I would guess that by removing and reassembling the purge valve triggered something in favor and now the EVAP monitor has set readiness- for now!
However, I'm still stuck with the P1174 code
I went ahead and replaced the CCV (crankcase vent valve) thinking that possibly it has an internal problem, I've reset the fault memory, so now it's only a matter of driving the car and see if the CCV will do the trick.
Attachment 640759Attachment 640760Attachment 640761Attachment 640758

****UPDATE*****
So, the check engine light came on the day after. This time with two codes: P1174 once again and now a new one P1423. P1423 seems to be related to 2nd air injection system, I will need to check into this. PLEASE HELP!