exhust/engine prob

[Bub]

alright, so tonight, i installed my rnr turbo back, no cat, and everything seems great, except i should of used some gasket sealent for the turbo to downpipe, but i can do that later.

the most imporatn problem is,
after i got done install, i let it warm up, rev it upa lil, then took it for a spin, drove around for a few, then started puttin on some gas, spool was nice, sound was great, and then a pop, not sure if it was because i was runnin lean, or because of rich,
i was thinkin that since one of the 02 sensor isn't connected anymore, that my egine might be giving too much fuel, and it lik back fired, or i maybe leannin out, i don't have a EGT gauge, and rely on the air/fuel, which shows rich? no any solutions, was it just becuase the exhust isn't all bolted tightly? or the no cat? or the o2, anything can help thanks

 

[gsx_tuner]

Are you running open downpipe?

 

[Bub]

naw, the downpipe is closed, although the seal is probibly not as good as it should be, (there is more than likely a leak)

 

[gsx_tuner]

Usually the computer will try and learn its' new changes. Have you allowed enough time for it to figure this out? Does it backfire all the time?

 

[Bub]

yah, i was thinin about that too, about the self learned thang, and well i only drove it for like about 3 mins, then gunned it, which is when it popped, after that i was kinda scared to gun it, untill i posted the question, but i did drive home from my friends house(where i installed it) which is about 8 miles, the car ran fine, not rough of anything else. so would it be learned now? or should i still kinda be steady on the throtal?

but yah, i don't think i gave it enough time to learn

 

[gsx_tuner]

As long as you don't have a CEL, and it seems fine when you drive it regularly, I would say 8 miles is more than adequate time for the ECU to figure things out. Go get on it, and if it backfires again, you might want to adjust your CAS.

 

[Bub]

alright, im still commin up on all the tech terms, i'll call myself a beginner in the tunner world, so if i could get some definitions on what a CEL, and the CAS

 

[gsx_tuner]

CEL=check engine light
CAS=cam angle sensor

The cam angle sensor just adjusts when to fire with the timing.

 

[Bub]

so i drove the car today, it backfired once, but after i was done with classes, and tried again, everything was fine, it pretty great, thanks for the help (=

 

[Tommy31]

Seems to me that since you are running no O2 that you would definitely be running rich all the time. Running rich leaves unburned fuel in the exhaust that is normally burned up by the CAT. Since you have no CAT that unburned fuel is left in the exhaust pipe, and man that stuff is really hot. It would love some air to be able to finish burning.

That's what causes backfire. Since you do have an exhaust leak because you don't have proper gaskets in it you are getting even more backfire.

There's not much you can do to get rid of it entirely. Definitely put an O2 back in ASAP (running too rich all the time will eat your piston rings and eventually you'll loose compression in the cylinders).

But do expect some backfire based on your setup.

 

[90DSMTurboFWD]

are you supposed to just use the gasket or are you supposed to put some sort of sealant on there too?

 

[Tommy31]

Just a gasket. No sealant is necessary.

 

[2GeNTSi]

Lol good thing I didn't put my downpipe on, I got mine from Extremepsi for 200 shipped but the gaskets and bolts were all backordered. It's Tuesday, I got it last Monday so I'm pretty anxious to put it on, the stuff should arrive tomorrow at the shop so I'll call them and hopefully I'll get it by Friday. I'll probably won't be able to install it until Sunday though because I have work at 5pm on Fri and Sat and I won't get the part until 3pm, can't do it Sat morning because my bro's VR-4 is being worked on by my Dad taking up the whole garage. I would do it outside but I hate working outside, if it was something like installing something in the engine bay it would be fine but I don't want to be under it outside.