patching exhaust leaks

[96Cobracomander]

Hey here is my situation im like 2 months over due on my inspection for the car...

I had a bunch of codes and i fixed all of them except for a lean bank 2 code
and i know the car has an exhaust leak before the up stream 02 sensor and i already checked all vacuum lines and everything after the MAF to make sure i wasn't getting extra air, and i cleaned the MAF with electrical contact cleaner ect.

so all i have left now is this leak to get rid of this code so i can get the car back on the road, how can i patch an exhaust leak where ever it may be?

i am a plumber so i have acess to high temp furnace cement would that patch anything just long enough to get an inspection done?


I have a whole brand new exhaust waiting to go in but i want the inspection done first

 

[98$vt]

is that a lean code for the o2 censors?
i had a bank code for the o2 being bad before i dont know if it is the same as what you have tho

 

[fast ford brian]

My buddy's Cobra had a small leak right at the O2 sensor bung and caused his code .

 

[mwolson]

A smoke test is your best bet. Find a shop with a smoke tester and you will know where the leak is within a few minutes.

If you can't find a smoke tester, you can try this: https://www.youtube.com/watch?v=zMok2y05jNE

I'd plug one tailpipe, and then start smoking. It might take a couple of cigars...

 

[mwolson]

You might also want to check your motor mounts. I had a broken one that allowed the engine to flex enough to cause a leak at the manifold donut.

Prothane mounts in there now.

 

[96Cobracomander]

p0174

 

[mwolson]

An exhaust leak could cause this. Smoke that bad boy out.

 

[96Cobracomander]

well most likely sunday ill have the time to do this... as for patching any leaks you think high temp furance cement would hold for a week ?

 

[mwolson]

Depends. If the root cause is a broken motor mount, no.

 

[96Cobracomander]

well i found the leak to be coming from driver side exhaust on the flange where the mid pipe meets the manifold, so i got some high temp furnace cement and slathered a whole bunch on the flange where the ball and socket are and i now fixed the lean code,

But of course 2 more codes have ascended from hell... P1443 and P0420, you think either of these are related to each other? pretty random that they'd jump pop up like that after i fix a lean code

 

[mwolson]

Make sure you check your driver's side motor mount or you will be right back in the soup soon if the motor mount is broken. Check the other cone too, while you are at it.

P1443 and P0420 are not related to your exhaust leak. P1443 is an evap code. Something is plugging one of your evap hoses or the purge valve is stuck closed.

P0420 means your Bank 1 catalytic converter may not be working correctly. Could be a bad cat, bad rear sensor, bad wiring, or a bunch of other things. First thing I'd do is swap the rear O2 sensors to see if the DTC follows the sensor.

 

[96Cobracomander]

after some reading i saw the most common cause of P1443 was this little sensor
1996-98 Mustang Fuel Vapor Canister Flow Sensor at LRS - Free Shipping!

so i just put a new one in and i have a feeling that isn't my issue, when i took off the 2 vac lines, i remember reading that if the line is blocked itll toss a code too so i decided to try to (try not to laugh) suck and blow on the tube coming from the purge valve, i couldn't push or draw any air from it like the valve was close, and this is while the engine was running (cold start)

any one think i still have an issue and should replace the purge valve? or does it not open till engine is normal running temp?

 

[DVJ38]

The purge valve wont open until commanded by the pcm. It is commanded open during cruising only, iirc. If you want you can take off the hose on both ends and blow through it I guess. However, I must say that these evap problems are almost always either a cracked line causing a leak, or a bad solenoid/sensor. I've only had a plugged vent ONCE, and it was due to a spider creating a web in there lol.

 

[mwolson]

Mine was a vacuum leak, found with an evap system smoke test, but it was a different Evap DTC.

 

[96Cobracomander]

well i replaced the flow sensor and 01443 is gone now

still have p0420 throwing a code,

so i went under the car and swapped the down stream sensors (both hooked up to MILs)

as soon as i did the swap i started the car up and threw a code p0174

p0420 is a bank 1
p0174 is for bank 2

so i think its a safe bet to say that the 02 in the rear is no good, what do you guys think?

 

[mwolson]

Seems that way to me.