OK so on my 02 I-35 I recently gutted the front pre cat and reinstalled it about a month ago. But in the process I ended up breaking about 3 bolts off in the exhaust manifold/pre-cat connection. So basically only 2 bolts are holding the thing on at the manifold beneath the 02 sensor. I have no idea how to get the broken screws out and install new ones other than to get another exhaust manifold and get pre-cat bolts from a dealer. So ive been driving the car and there is clearly an exhaust leak there as i hear and smell it and my gas mileage has went down terribly. I almost sounds similar to the 3rd gen maximas where they had an exhaust leak lol. So now gas mileage is terrible, and the 430 and 172 codes for running too rich are popping up. Need to get this fixed asap.

 

Did you install a spark plug fouler? Because if not, the O2 sensors are gonna read the same value, making the computer think that the engine is running rich.

Did you gut the rear cat as well?

At this point, I would take it to an exhaust shop so they can drill out the bolts and install new ones.

 

[QUOTE=SubwayVQ;9158692]Did you install a spark plug fouler? Because if not, the O2 sensors are gonna read the same value, making the computer think that the engine is running rich.

Did you gut the rear cat as well?

At this point, I would take it to an exhaust shop so they can drill out the bolts and install new ones.[/QUO

No i havent installed an 02 sim yet, and i didnt gut the rear cat because it is fairly still new.

 

The O2 sim should fix the codes. As for the leak, you may have to get creative. I don’t know how much working room you have, but cheapest bet is trying to fill the gap with epoxy or RTV until you can truly fix it.

 

OK kool I do have some RTV around, what about the exhaust tape do you think that would work too. Ive got the black epoxy though for the valve cover gaskets. Do you know of a link to order the 02 Sim?