TDsi

just purchased an 04 si about three weeks ago. on wed during my drive home from work i started to hear a thumping noise coming from directly under my seat (about where the cat converter is) during downshifting and engine breaking. i pulled over and checked around but couldnt really tell what was wrong. i drove it home with no problems except for the noise. due to work and the lovely hurricane that paid a visit last weekend ive been busy all week and didnt have much time to look at it until the weekend. thursday i drove it to work and it was fine besides the noise, same with friday morning. on the way home the engine shut off while sitting at a light. thinking i just stalled it and didnt realize i started it back up and continued on. about a mile down the road it did it again. started back up and made it another couple miles before it did it again. pulled over and started looking around. nothing out of the ordinary so i tried to start it up but now i noticed it needed some gas to get it going and i had to keep it above 1500 rpms or it would shut off. at this time i was about fifteen minutes from my house so i just wanted to try and get it home. got back on the road and it was fine until i ran into some traffic and i ended up pulling into a parking lot because i couldnt keep it from stalling in traffic. once i parked and turned it off i couldnt get it to start at all. called a friend to give me a hand. we looked it over and couldnt really find anything. eventually it started back up again and i gave it one last chance to limp it home but it didnt make it very far before dying again. at this point it wont even try and turn over. we push it into a parking lot and call it a night.

im not the most mechanically inclined person, more of a learn as i go type and this is my first civic so i did some searching when i got home and was thinking maybe it could be the tdc sensor but not totally sure so i figured id ask for some guidance on the situation from you guys. sorry for the long post and thanks beforehand for any help/suggestions.

howaaj02

Had the exact same problem with my 2002 LX... The cat is definitely a part of the problem. It's one piece with the exhaust manifold on the LX... My manifold was glowing red hot and had a huge crack in it. I didn't realize it until it was so bad that the car stalled and died at a stoplight, just as you described. The car goes into limp mode (reduced air/fuel...just barely enough for the engine to run to prevent damage), which is why you could restart it and it would go for a while, then the computer realizes whats happening again and says "nooooo!! something is wrong here!"

I replaced my manifold with a cheap header as a quick fix, but the real problem was the TDC sensor, which I replaced, and fixed the problem immediately. I don't know exactly how the cat/manifold issue is related to the TDC sensor failure, I would love for someone to figure that out and explain it to me.

Have you read your OBD codes properly? Mine was P1361, specific for TDC sensor intermittent signal interruption. P1362 (TDC sensor: no signal) is also relevant. That could just be loose wires/plugs.

Replace your TDC sensort, there's a great DIY guide on here somewhere. It may cost you a considerable amount in labor to pay someone else depending on where you go. It's not a tough job, just requires some patience and organization.

Probably should have your cat checked out too. I ditched mine, so I never found out if it was clogged or what the deal was.

lazlong

Go to Autozone and have the codes read. They do it for free. Post up the codes and we can go from there. Don't just start throwing parts at it.

gearbox

iTrader: (95)

i would assume the excessive heat caused the sensor to fail. heat can be very damaging to nearby sensors and wires.

TDsi

i havent been able to run the codes because the car is sitting in an apartment complex parking lot and will not start. when you try and start it up all i get is a "thump" as if something is bound up keeping it from turning over.

howaaj02

Yeah...it's not gonna start if TDC sensor is shot. Based on what you described I think it's almost definitely the main problem, but you really must verify your codes first. OBD-II code readers are usually at least $100 retail. They sell them at Wal-Mart...not to suggest anything less than kosher, but they usually take anything back with a receipt. If I were you I would try to convince a parts store or repair shop to let you rent one (if possible...I think some places will do this). Or you can ask around among your friends to find out if anyone might know a guy who knows a guy who has one...

lazlong

You can get a basic code only reader starting at $50.