Eec Codes

[Ranger5.0]

Ok, so Im runing an OBDI controler for the engine in my truck. It recently started runing poorly and the fuel milage went down the drain. the last time i checked all the codes everything was good to go code 11 for each test. Now Im getting codes 12,41 and 19. The first is an issue controling engine rpm during the fast idle test. the other two are for the lh and rh HEGO sensors. both are reading lean and the left one isnt switching. The drivability issues are as follows. Engine runs poorly untill it reaches 170F. Its veary hard on gas now and wont rev past 4800rpm. I just found that my brake booster is leaking badly and the rh exaust header has a bad leak upstream of the sensor. Anyone have any therorys?

 

[Earl43P]

Brake booster is vaccum driven.

If it's leaking, plug its vaccum hose and see how it runs. I'd think a huge vaccum leak from a leaking brake booster would make it run lean. Un-metered air and all that.

Not sure if the header leak will affect the O2s or not. It will cause uneven heat dissipation and crack the head/gasket though (very common when a stud is broken off).

 

[Ranger5.0]

no broken studs, header's leaking at the collector, the welds in the center where the 4into 1 are falling apart. so what would cause the left sensor to just up and die both sensors are only a year old

 

[crazy8ranger]

ur o2 sensors r most likley NOT the problem. if u have leaking exhaust gaskets and or cracked headers, air is able to enter the exhaust streem, yes exhaust blows out this crack but also there is vacum between exhaust cycles (why vacum u ask it has to do with cam timing and valve over lap) thus air is pulled in, the o2 reads this "fresh" air and thinks ur engine is running lean. the computer sees this and commands more fuel (on time for the injectors) causing your lean condition. in your case u must have one HECK of a large leak to cause your problem u are having. but my key board diagnosis would have to say that your booster is one of the main causes for the lean condition, get your exhaust welded up and that booster replaced BEFOR going out and getting a new o2 sensor. (ull have to get these fixed n e way so y waste $$$$$$, if u put parts on a vehicle and dont know whats wrong with it then ur just whats called a "parts replacer" rather than a Technician O by the way im ase certified in a few areas and engine electrical and electronics is one of them, hope this helps in advance
jason

 

[Ranger5.0]

ya, im a 3rd year heavy tech aprentic I was just looking for some insight and opinions. Im replacing the boster soon as it gets in, and taking the shat headers and replacing them with somthing a lil heavier and less likly to fail on me...allthe time. lastly I need to find out why it says the one sensor isnt switching, that kinda sounds like its dead to the world or there is a bad conection, does it not?