my car has a noticable stumble between 2500 and 3000 rpms while under load. i have been doing alot of mods lately, head, 4% pulley to go along with the 15%, header mod, custom 3" exhaust, upgrade mth. this code is a powertrain: injector circuit cyl 6 intermittent. the car ran very well after mods, went on a long trip, car has slowly been getting worse, i put the one ball exhaust on, stock ecu file, changed the bpv mod back to stock, still the same problem, i don't understand the cyl 6 part of the code description. anybody experience this before? car has 44,000 miles. my first thought would be bad injector, but sometimes the problem is caused by some other problem.

cheers

 

are you running stock or upgraded injectors??

 

stock injectors, i did a search and found that this code is "secondary upstream manifold air pressure sensor low". my code scanner must of gave the wrong def. of the code. i did notice residue around the intercooler boot on the pass. side, i am going to trace all vacuum lines. one other thing, i am only making 16 psi of boost running 19% pulley.

cheers

 

*****...well sounds like one of two things I have run into...one the easy fix. your Up stream map sensor has gone bad...weeee!....

or

you have a vacume leak BEFORE the SC. The SID maybe loose or the clamps for the tube on the by-pass valve may have given up....I just fixed an issue like this a little over a week ago...if you can get it replaced under warrenty then WOO HOO! cause it's not hard work...but time consuming. make sure you have the code when you take it in

hope that helps

 

hello tuls,
i did a head job about a month ago, i think i should retrace all the steps and make sure i have all tight and no vac or boost leaks. as i stated this problem is gradually worse, even though the stumble is very noticable the car performance has dropped consideribly, about 1 sec in a 1/4 mile. i am a carb guy and am trying to get a education on efi and forced induction.

cheers

 

I got that code on a stock car after I zip tied the bpv shut. It went away after cutting the tie.

My modded car car with mth did not get that code.

It is possible that the sensor is leaking at it's mount, the connection is bad or the sensor is bad. You can try swapping the the tmap sensors, I think they are the same.