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P0171 (spark plugs and manifold gaskets change)

Posted: Mon Apr 01, 2019 3:12 pm
by alanskytraveler
Hi! I have changed spark plugs, put the manifold on new gaskets, but now there's P0171 code (means that, on the first bank of the engine, the fuel system is running weak or a vacuum leak exists near this side of the engine. A lean condition occurs when the engine either receives too little fuel or too much air). We checked all lines with mechanic and there isn't any vacuum leak. The fault is gone if I accelerate the engine for 20-30 seconds. Where's a problem?

Re: P0171 (spark plugs and manifold gaskets change)

Posted: Mon Apr 01, 2019 6:33 pm
by ds32928

Re: P0171 (spark plugs and manifold gaskets change)

Posted: Mon Apr 01, 2019 7:13 pm
by Webmaster
Your mechanic can't figure it out?? Try a better mechanic but yeah that link is helpful too.

Re: P0171 (spark plugs and manifold gaskets change)

Posted: Wed Apr 03, 2019 3:30 am
by DanfromSterling
There are vac lines that run down the center of the manifold. Trying to slide and position manifold back in these lines can get caught under manifold then when manifold gets tightened down could pinch. I accidentally did this on mine. Pulled manifold and replaced the vac line payed more attention when reinstalling next time to make sure in channel and not pinched. I took the vac assembly line off parts car as lines totally crushed.

Re: P0171 (spark plugs and manifold gaskets change)

Posted: Wed Apr 03, 2019 6:23 am
by alanskytraveler
Thank you!