would not having the bcs cause fuel trim problems

[Orangedsm95]

I have been trying to find what is causing my car to throw the fuel trim code. I tested the front o2 sensor and it tested good. Switched injectors out to the 450's and still had the same problem. I was looking over all the electrical connectors to see if there was any plugged and noticed that the bcs was completely gone. Would this cause the fuel trims to be off at all? My af ratios jump from 14.1 to like 15.3 and you can feel the power loss.

 

[gofer]

Are your AFR's jumping back and fourth between 14.1 ~ 15.3:1?

 

[Orangedsm95]

Are your AFR's jumping back and fourth between 14.1 ~ 15.3:1?

Yea and than you can feel the car kind stutter a lil bit.

 

[blackhawkgsx]

you either have a crack in the manifold or o2 housing before the o2 sensor or you have leaky injector orings .do a boost leak test first then if that checks out check the manifold and exhaust for any cracks or leaks pre o2 sensor . i have had this same issue and it was corrected with a new manifold and injector seals for the head. hope this helps.

 

[Orangedsm95]

you either have a crack in the manifold or o2 housing before the o2 sensor or you have leaky injector orings .do a boost leak test first then if that checks out check the manifold and exhaust for any cracks or leaks pre o2 sensor . i have had this same issue and it was corrected with a new manifold and injector seals for the head. hope this helps.

I did a boost leak test last week when the issue first started and found out the bov is leaking out of a small port on the back side and i cant get the car to hold more than 10psi. Could that be the issue? Because the af ratios jump around well cruising and accelerating but it doesnt happen at wot. Also when u say the injector seals are u referring to the upper or lower seals? Ive replaced the lower ones recently.

 

[gofer]

Your AFR's are supposed to jump around while idling and cruising, thats what your car does in closed loop mode. The ECU watches the front o2 sensor voltage in closed loop operation trying to maintain a 14.7:1 AFR mix, thats why I asked if it was moving between 14.1~15.3:1 because thats what its supposed to do. When you go WOT or put a load on the car (go up a hill) your ECU will go into open loop operation. When it does so it ignores the front o2 sensor and uses its preloaded fuel trim/timing maps to determine the AFR and timing advance.

What fuel trim CEL code is it exactly?

 

[Orangedsm95]

Your AFR's are supposed to jump around while idling and cruising, thats what your car does in closed loop mode. The ECU watches the front o2 sensor voltage in closed loop operation trying to maintain a 14.7:1 AFR mix, thats why I asked if it was moving between 14.1~15.3:1 because thats what its supposed to do. When you go WOT or put a load on the car (go up a hill) your ECU will go into open loop operation. When it does so it ignores the front o2 sensor and uses its preloaded fuel trim/timing maps to determine the AFR and timing advance.

What fuel trim CEL code is it exactly?

P0170 fuel trim malfunction bank 1 is the code thats coming up. Also P1400 which the MDP sensor malfunction. Another thing is that i have 550 injectors, a walbro 255fp, aero fp regulator and my settings are still postive on my afc +8 at 800rpm and range from +15 at 1400rpm to +6 at 7000rpm.

 

[blackhawkgsx]

having a leaky bov can have a slight effect but wont give you the fuel trim cel. it dose not matter what injector seal top or bottom i just replaced them all with the genuine mitsu part #. but the code you are refering to means you have an exhaust leak pre o2 take you exhaust mani off and inspect the inside most likely the collector has a hair line crack you may not be able to tell from the out side . also make sure the o2 sensor is all the way in. check the gaskets etc...

 

[Orangedsm95]

having a leaky bov can have a slight effect but wont give you the fuel trim cel. it dose not matter what injector seal top or bottom i just replaced them all with the genuine mitsu part #. but the code you are refering to means you have an exhaust leak pre o2 take you exhaust mani off and inspect the inside most likely the collector has a hair line crack you may not be able to tell from the out side . also make sure the o2 sensor is all the way in. check the gaskets etc...

Are you sure that is why its pulling that code? I really dont want to have to pull the turbo off if i dont have to. I know one of the exhaust manifold studs are broke off but theres no carbon build up like its leaking in that area. The turbo to manifold gasket and o2 housing gasket are maybe a year old. Im getting tired of messing with this pos. I really wish i could afford another car right now because it would defiantely be part out time.

 

[dsmdeliveryboy]

Is your MAS hacked? I know having the MAS hacked will throw a fuel trim CEL if it isn't compensated for on the AFC because you'll be too lean at idle, and I've heard having the BCS out can mess with your fuel trims slightly as well. If you need a BCS PM me, I have an extra.

 

[Orangedsm95]

Is your MAS hacked? I know having the MAS hacked will throw a fuel trim CEL if it isn't compensated for on the AFC because you'll be too lean at idle, and I've heard having the BCS out can mess with your fuel trims slightly as well. If you need a BCS PM me, I have an extra.

All the honeycombs are still in the MAS but someone messed with the screw on the bottom of it. I did a lil researching and found this 2G MAS Screw. According to rre turning the screw all the way in will make the car richen up and i tried do that but it didnt make any difference.

 

[blackhawkgsx]

dont part it out bro diagnosing and repairing the issue feels great when your blowing past mustangs but just pull the manifold and check that for cracks you dont need to remove the turbo it will take about 45 mins... clean it off really good and inspect carefully

 

[Orangedsm95]

dont part it out bro diagnosing and repairing the issue feels great when your blowing past mustangs but just pull the manifold and check that for cracks you dont need to remove the turbo it will take about 45 mins... clean it off really good and inspect carefully

Im not parting it out. I dont have another car yet. But ill give it a try and see what happens.