Failure to pass CAT test on computer system

Z71Silverado · April 27, 2015

Been having this problem for a year now. My pile of dung still won't pass an NYS inspection. My truck's driver side header had the two front bolts break off from being rusty. My truck ticks until it warms up to running temp. Would this keep the computer from passing the CAT test and have it always be at "Not ready"?

Z71Silverado · April 27, 2015

Already replaced O2 sensors, new ECU, new catalytic converters.

Chris · April 27, 2015

There is a driving cycle to set it all. It is a pain. I would fix the leak then try it

Z71Silverado · April 27, 2015

Yeah. I've done the driving cycle at least 100 times.

Z71Silverado · April 27, 2015

I also don't think I can fix it. The bolts are broke off into the block. It will take some serious work to fix it. I ask this question because I would like to know if this could be the problem before I spend a ton of labor hours working on it.

Chris · April 27, 2015

Do you want the quick answer? New exhaust manifolds and studs. Or drop the entire Y-pipe (pain in the ass by the way, i got pissed and broke out the SawZall) and then extract the studs and replace them. I like option 1, more expensive but will be easier.

Z71Silverado · April 28, 2015

If I was going to take the time to try and fix the headers I would rather just buy aftermarket headers. Then have my mechanic put them on. What are good stainless steel headers to buy that will increase performance but not break the bank? $400 or under if possible.

Chris · April 28, 2015

With emissions you are stuck to short tubes. Not much gain. Basically just look pretty. Might gain a little.

Z71Silverado · April 28, 2015

With emissions you are stuck to short tubes. Not much gain. Basically just look pretty. Might gain a little.

Ahhh, no point in wasting money on aftermarket then. I should just fix the OEM headers then.

Chris · April 28, 2015

Ahhh, no point in wasting money on aftermarket then. I should just fix the OEM headers then.

Easier to replace the assembly.

uh6tdrvr · May 4, 2015

If I was going to take the time to try and fix the headers I would rather just buy aftermarket headers. Then have my mechanic put them on. What are good stainless steel headers to buy that will increase performance but not break the bank? $400 or under if possible.

I think if you put a one infront of your price you can find a really good set of ARH's but it sounds like either way your going to have to do the bolt extraction.

Z71Silverado · June 16, 2015

Could a bad fuel pressure regulator sensor be the cause of this problem? I finally have a code coming up and staying constant. It's saying it's a bad fuel pressure regulator sensor. This made sense to me that this could be the problem. If the computer system is pumping too much fuel into the engine the emissions are going to be too high and fail the CAT test, correct?