All,


So...I had a bit of an issue with my Coolant By-Pass hose...you know the Short 2" Dia or so little hose that connects to Aluminum Thermo Housing and then to the Engine Block at roughly 45 deg. with those pesky Spring Clamps....anyhoo...I fixed it but it was a pain in the ****.


Well...Filled her back up...no leaks...pressure good...engine still running hot though..??? But NO leaks...


Well the engine suddenly ran real rough on Idle....Engine light came on...etc.


I hooked up the OBD Reader and got the dreaded P0171 & P0174 Error Codes and RESTRICTED PERFORMANCE flashing in my face...FFS..!!!


There were also....Random Misfire Codes for ALL cylinders and a few other codes...But I won't list them all.


So...I checked for Vacuum Leaks...couldn't find any...Cleaned the MAF Sensor thoroughly...cleaned the Throttle Body...Cleaned the Entire Intake Tube...and checked all connections.


Still recieving the errors....WELL....just by chance I grabbed the little plastic hose that connects to the Part Load Breather on the Driver's side Valve Cover....you know the one that every is cleaning with a drill bit...




When I noticed that this tube was broken....I obviously broke it messing with those damn spring clamps on the By-Pass Hose.




So I grabbed the other end....and put a smaller plastic hose inside...connected it to the other end on the Valve Cover....and that FIXED everything. All the Codes were gone...car ran smoothly....Emissions Test Successful....All Misfires GONE..!!! Engine Light OFF..!!! Restricted Performance Warning....GONE..!!!!


SO...Does anyone know WHY IN GOD's NAME would a simple Load Breather cause all that trouble..???


I have read SOOOO many posts on here with people having these Codes come up...and Restricted Performance...and trouble shooting for HOURS or even DAYS...with no luck. Not to mention spending money on parts they may not need.


Anyway...that little plastic hose is bound to go sometime...so you all keep your eyes on it. I still need to fix mine properly...but this will do for short time at least.

 

Hmmm, ... I'm putting up with somewhat high fuel trims that occasionally will throw a P0171 and RP. Diagnosis points to a vacuum leak(s), that I've yet to nail down. I've been planning to replace the O-rings on those breather tubes (as soon as I figure out their size), but never considered the tubes themselves to be a potential source of leaks. I think I'll try just taping over the holes in the throttle body and intake duct, and see if the trims change.


The reason the leaking load breather tube would cause so much trouble is that it will introduce air into the system that didn't go through the MAF sensor. So the ECU doesn't know about it and doesn't program a proportional amount of fuel. You then get a lean mixture in the combustion chambers which is compensated for with the fuel trims. Too much trim and you get the codes. But the trims can only handle just so much; beyond that and you're stuck with a lean mixture. If the situation continues to worsen, the engine will run like crap.


Great to hear that SOMEONE has been able to clear-up those codes. Congrats!!! & Thanks.


BTW: I just replaced that hose last week (it was a time bomb on a reeeeally short fuse). What friggin' royal PITA!!! Took me two and a half hours of "try this - nope, that didn't work; try that - nope, still not enough clearance." And for God's sake, PLEASE don't let me drop the coolant manifold screws!!! In the midst of all the creative problem solving, I forgot to inspect what I could see of the valley hoses. Nuts. Those things really scare me. Hopefully, they're in as good condition as the hoses behind the engine which are all in apparently great shape.