Getting the P1124 and P1126 codes. Advise?

[Wehrmachtoberst]

I've got a question for everyone! I have a 99 Boxster 2.5 with 86K miles on it. My CEL popped on with the codes P1124 and P1126. No rough idle. No smoke. No stalling. Perfect acceleration, perfect shifting. Runs like when I bought it, which is awesome!! Nothing to indicate anything is wrong. I tried taking off the oil cap (thinking AOS) and was told that if the RPM’s dropped then that was ok. It dropped maybe to 750-700 (from a normal 800 range). Cannot hear any hissing or anything.

I bought her back in February and have changed the oil and filter but I did not change the fuel filter and have no idea when ti was last changed. This is being done this week. I was thinking MAF but I am not too sure. Was also thinking possible the AOS is *starting* to go.

Now I have been using my A/C and it does idle down a bit when taking off but ONLY when the A/C is on. I have read that it could possibly be the battery but why would that throw a code? Every other time she runs perfect, just like when I bought her.


I am totally perplexed at this. Thoughts on the matter?

[JFP in PA]

The codes are for the same problem on opposite banks, namely the system is running too lean. Usually either a vacuum leak in the system or low fuel pressure.

[boxster newbie]

I have perservered, thru the same codes, done an aos, bad oil filler tube, and , done a fuel pump, fuel relay etc. I had bought spark plug tubes , and attempted to remove, them, still suffered these same codes. finaly got brave and a little, rougher broke 4 out of six to remove them , new tubes and o rings, in and no codes.must have caused a vacuum leak, trying the first time. by a smoke machine? you can change a lot of parts, for 1000$

[Brian Minson]

Just had those codes pop on my 2001 Boxster S, and sure as $h!t found a leak in my intake. Just make a $5 smoke machine, find the leak, and fix it! Here is how I made my home made smoke machine and fixed my Boxster.

https://youtu.be/lneTKq-8oTw

Brian