Was driving home on the freeway, doing about 80 and I floored it, engine made all kinds of noise but made almost no power, so I backed off and around 50% it started making all kinds of power again. I didn't think too much of it, planned to look into it when I got home, but then, when I got off the freeway, driving along it started to sound like 6500rpms when the gauge only read about 4k, so I knew something was up and suddenly it just crapped out, wouldn't rev past 1500 or so and there is a loud hissing sound from what sounds like the rear bank exhaust manifold or possibly the flex section blew out. Its too dark out there too see right now, but I have no idea why this happened. The ECU through only one code, and that's P0325 Knock sensor, but I know the knock sensor isn't causing all this and I know the ECU just loves to spit that one out for no reason. My dad was saying that its possible that the Cat converter got clogged and the exhaust just made a new way out, hopefully not damaging anything inside the engine along the way, but I don't know that for sure and can't really look into it until morning tomorrow. Any suggestions greatly appreciated, sorry for the none y-pipe/intake/photo shop related post, but I consider this more important.

Cliffs: Car lost power above 50% throttle, loud hissing noise presumably exhaust coming from rear bank/flex section, car no like to run but it idles just fine. (just noisy)

 

BUMP for Thursday.

 

i had similar problem before. i was cruising arourd 75mph and RPM started drop for no reason, the car felt it was gonna die but it came back up.

i had CEL as well, one of them was knock sensor. and the other one was engine coolant temperature sensor malfunction. i got both sensor replaced and car runs like normal again.

btw i had horrible gas mileage back then... i was getting at most 300mi/tank

hope this help.

 

The thing is though, my enghine is making a lot of noise right now, I can't fully tell is its a hissing from air leaking or it almost sounds like it could be a bad bearing hissing/grinding noise, not sure. A few days ago my engine sounded like it had a friggin turbo on it, at above 3k if I gunned it there would be a high pitched sound almost like a turbo spooling up that was much louder than the alternator, so I know it wasnt that. Also, my engine water temp was reading 200*f which is well within normal range, so I dont see how it could be water temp sensor, but who knows. I'll go check codes again and see if there are any more.

 

I never get that. At most 265 miles per tank...

 

Have you had a chance to inspect it better yet?

 

I agree with your dad.....maybe the cat got clogged...maybe the air came out of the exhaust manifold or y pipe and caused a leak(the hissing sound) in from one of the gasketts??

 

put you hand over the muffler and see what happens.

 

my ks is out but car still pulls like a champ! Massair maybe?

 

I can still see exhaust fumes coming from the muffler, I'm thinking I might pull the cat off and see what happens, if it cures it then I know the cat is dead, otherwise I'm still clueless. I dont think it is the mass air since I dont see how that would make noise, and as for inspecting it, I really couldnt see anything but I tried to feel if the flex section was leaking and it didnt seem to be. I think it might be up where the manifolds attach to the y because you can smell exhaust very strong in the engine bay. Thanks for the suggestions everyone.

 

maybe the egr tube broke and you have leaking intake and exhaust manifolds.

 

Great thought, would this cause huge loss of power? Another idea I had was maybe my flex section collapsed on itself, but that also requires me getting the cat off which is neither fun nor easy, but hopefull I'll have time either tomorrow or on Monday.

 

300/tank, how much you get now? highway/city ratio?
I get about 300/tank too 40%HW/60%CTY

 

Well, gave up on it and took it to a mechanic today and he said that the EGR back pressure transducer was completly gone, the diaphram was ripped apart and the vacuum hose had come off, so they are going to replace it. Anyone ever had problems with these things before or am I lucky number one?

 

i have one but the small vac line melted. id have to check if the diaphram is good. do you need one?

 

nah, they ordered one for me, friggin $97 but ohwell... thanks for the offer though.

 

dam they are expensive!

 

Yeah, now you know how much to sell yours for, hehe.

 

Yea, sounds like youve got ur problem found