Hi and thanks for reading,

I have a 2000 neon that I have owned since new. It currently has 235k on the clock and no signs of stopping. A few weeks ago I was driving into a state park. They had this ridiculous triangle speed bump that was awefully high. Going over it very cautiously I suddenly heard the exhaust get loud and a ping. I was stunned and immediately thought I hit something. I parked and looked underneath. Sure enough the exhaust broke off where it was clamped on the flex pipe. I have been going over speed bumps in parking lots and such and never had a problem. I was pissed to say the least and had to drive it back home, 50 miles, and the car was so loud. The break was just after the cat where the flex pipe connects. The car was vibrating when I accelerated and sounded awefule, I was embarrised. I had a friend put a new flex pipe on and it still sounded loud and the exhaust note was off. Then I started smelling that rotten egg smell off and on as well as exhaust smell when its idling. I still think there is a leak somewhere, maybe on the front pipe where the exhaust bolts off the manifold? I also think the cat might be toast too as the engine light came on last week. I have had it parked ever since till my friend can look at it. I am just pissed that this happened and dont wanna keep driving it while the engine light is on. Do you all think the CAT took a hit when I went over the speed bump and drove it home after? It was running just fine before this all happened.

 

Rotten egg smell is normally the cat. What code is popping up?

 

Yeah, I figured the rotten egg smell would be the Cat. I havnt found out the code yet. I have to wait till my gf's brother looks at it. Hes a master tech and normally services my car when it needs more than the typical fixin. He will get the scanner on it. Luckily, I have my 85 Mazda Rx7 to use while the neon is parked.

 

My friend came over with the scanner and got the code. It is reading 0441 which comes out to Evap emissions incorrect purge flow. He tried clearing the code, but it wouldnt clear out so he said it was a hard code. He thinks it might be the Evap solenoid which controls the burning of fuel vapors. He said it might be stuck open. So the code doesnt appear to be exhaust related. He did note my muffler sounding a little funky and the heat gun said the converter was heating up correctly and evenly. He thinks worst case a piece of catalyst might of broken off and lodged in the muffler. What do you guys think about the code?

 

If the lines are all good, it's likely the EVAP solenoid or the LDP.

 

Thanks, what do you mean by LDP? The lines are fine and not leaking. Rock auto seems to sell the evap solenoid for 27.99 by airtex and autozone charges 50 bucks for theres. I think rock auto is the better deal.

 

Non-NGC Neons had a LDP (leak detection pump) instead of the NVLD (natural vacuum leak detector).

 

Thanks for the info. I appreciate it. I still wonder about the exhaust issue. If I got a header and took off the stock manifold and made a straight pipe without a Cat I bet that would be better flow. I hollowed out the catalyst on the stock manifold as it was all broken and restricing flow. I did the piggy back spark plug non fouler trick with the O2 sensors on the manifold and drove it like that for 3 yrs and 45k with no engine light. On the 2nd Cat after the manifold I used a high flow CAT and magnaflow muffler. I noticed a big diffrence in throttle response after. I wonder if I can do that same trick with the header and not use a Cat, maybe a pre-silencer or something. I'm sure with that setup the throttle response would be even better.

 

I think I figured out the problem. I went poking under the hood and noticed a vacuum line disconnected. After searching around it connected right into the throttle body. I beleive its the line that sends the vapors to be burnt in the engine. I had the car running to warm it up before I connected it and when I put the vacuum line on the throttle body the car almost stalled then it idled normally. I shut the car off, disconnected the battery, reconnected and when I started it up the engine light went out. I drove about 70 miles so far with a few stops at stores and out to eat and the engine light hasnt come on since. So I think when I got my tranny serviced and my friend removed the lines from the cooler he must of nudged the vacuum line from the canister. Then somehow it popped off over the last month and set the code off. I guess I got lucky on this one and have my fingers crossed it doesnt come back on.