carbotdude

Is it possible that an exhaust leak would cause too much fuel to be dumped into the engine? The first time I tried to remove the starter, I had to undo 2-3 bolts on the exhaust after the header on the passenger side. That connection might be before an O2 sensor now that you mention it. I forgot to mention this is the 4WD 4 door variant of the SE-V6.

Hello I am new to this forum. I purchased a 1995 Nissan Pathfinder SE-V6 with the VG30e engine with a manual transmission and transfer case last year. I upgraded the coolant reservoir and battery after purchasing the vehicle. I had my valve cover gaskets replaced as they were leaking oil onto my starter motor and killing the starter June 2026. I mentioned to the mechanic that I noticed a 51 ECU LED engine code, which my research tells me points to fuel injector issues. After the repair was completed, the engine started running rough and dying after a few minutes. This first mechanic gave up on the car and told me to take it. The first mechanic said that he replaced the fuel injectors as well as the valve cover gaskets. I noticed that the exhaust is much darker than usual. This tells me the engine is running rich. I had a different mechanic take a look at the engine. After replacing a few hoses, the engine ran a little better, but not much better. The second mechanic mentioned to me that the engine is running rich on all cylinders by checking all of the spark plugs. This same mechanic conducted a smoke test and did not find a leak. I think he mentioned something about messing with an EGR valve/baffle or something and that did not change the engine behavior (I need to find a good picture of that part). At this point the mechanic told me he doesn't have time to look at the car. His biggest suspicion is that there is an undiagnosed vacuum leak. What do I do next to fix the rough engine? As far as I can tell, the rough running is at all RPMs, not just idle. I have never had so much fun driving until I got this car. I would like to get it running again. Is there a guy/shop in the New England area that knows how to work on these older Nissans? At this point, I am willing to sell the car to somebody that has the tools to work on it. I am beginning to think that specialized tools are required that I don't have, especially if the valve covers or engine block are warped in any way (how does one know)? The vehicle is sitting at a friends place 30 minutes away as I don't have room for a broken car.