Hi All,

Wow finally had the time to get the tranny back in and changed the alerternator and water pump at the same time. Was running great but had a slight vibration when going 50 +.. when to run the check on that, shifting to 3rd at speed to see if remained the same or not, when the truck stalled out. Just getting on the highway and got up to 45 and then, dead. It started back up and I was able to get back to my house, 1 ,mile, all the while it was surgering. Went out today and it starts right up, no sign of an issue but when you try to give it gas it lacks anything above 3000 rpms. Ugh,,, not sure where to start on this one, MAF, cats etc... anyone out there hav ethe same issue ?

Thanks

 

So here is where I am:

The Blazer will now not go over 5 mph.
It cannot rev up more than 3500 mph
If I step on the gas and let it off fast it almost stalls.
When driving it if I try to speed up it wants to stall out.

Checked the cat and the temp going into it was 376 and out was 390.. Figure that the cat is the issue but there doesn't seem to ba any exhause reduction.

Tomorrow I will unhook the y-pipe and see what happens but if it is the cat has anyone here welded one in instead of replacing the whole thing?

Thanks

 

My cat was a bolt-in replacement. with a flange just downstream of the joint in the y-pipe.

What makes you think your problems are with the cat?

 

Thanks for the reply. I read and researched the issue that I was having and it listed thing like the rotor, cap and plugs - all been changed in the last year.. fuel filter - will be changing that tonight as well as cleaning the MAF as potential issues. The cat was there as well and they have one of the test as cheking the temp at the input and output of it and if there was not a temp was the same or lower at the output then the cat was gone.. my input was something like 365 and the output was 370 so from what I was seeing that looks like the issue. BUT I also know that there may be other things that I don't know about to check. Which is why I am here....

 

More updates:

Went to NAPA at lunch and picked up a new air filter, MAF Cleaner and a fuel fitler. Sprayed the MAF and installed the new air filter. Blazer started w/o issues and idled file. Stepped on the gas and it ran right up to 3200 rps and then just seemed to not go anywhere else. When I let go og the gas peddle it stalled and then took a few tries with the gas peddle to get it started. I will change the fuel filter after work tonight but now I am not sure if this is fuel pr cat issue... any help would be great and thanks

 

Have you checked the fuel pressure yet?

 

not yet

 

It's the cat ugh.. pulled the O2 sensor out today and ran great, loud of course, but cracked right up without an hessitation or delay. So now to find a cat that will not kill me on price. I do have a welder so thinking of a universal replacement..

 

Glad you got it figured out! After market cats aren't too expensive, at least

 

The cat on mine was a bolt in replacement without having to replace the y-pipe.

As for vendors, do NOT use Ultra-Exhaust (https://www.ultraexhaust.ca/). The one I got from them had the mounting nut for the O2 sensor in the wrong place and they would not replace it.