Hey all,

So the maxima from hell keeps throwing me problems - by now i have learned to tackle them with the goal to make this beyotch run top notch (har har).

Anywho - i have a magnaflow 2.5" catback. When I idle and I rev the engine, I hear backfiring as I let the gas go. If I hold the gas pedal its not there, but once I realse I can hear it. Also when I take off I can hear it backfire a bit but once I pick more speed - it goes away.


hep?

 

per Wikipedia...
Afterfire (the proper term for exhaust backfires), occurs in engines that have an emission system malfunction (air injection system diverter valve), exhaust leak or unburnt fuel in a decatted exhaust system. When a driver shifts up and lets off the gas, the engine has a moment of running rich or with insufficient oxygen. This causes an incomplete burn which causes the fumes to explode in the exhaust system.

 

^^^^^^^^^............you have an exhaust leak!

 

Theres ur problem... get rid of that pos magnaflow muffler and get an oem or a 5th gen... is not backfire its more like reverse breathing....

 

i dont know why someone would search wikipedia for a car problem(not most reliable source, considering i could post that a thermistor is a cooler to put your drink in)...but i agree with it. backfiring in exhaust = rich mixture. which could be due to multiple things.

 

i go to my garage for a car problem. i go to wikipedia for thorough definitions that gives an explaination of probable causes of problems. if the info is correct, i don't care where it comes from. however, next time i'll just ask you instead...

 

thanks you should. then ill go to a more reliable source. like the FAQ or stickies on this site. or even nissanhelp.com. not wikipedia where any a**hole can post definitions of things.

oh and by the way...i wasnt trying to come off as a dueshabg at first, but thanks for being one back

 

very welcome!!!

 

Okay so - running rich or having a leak?!

Sheesh!






If I am running rich - how do I remedy that? Bad spark plugs? Coils? Something?

 

Is it more like a burbling sound? If so then that might be normal. Part of the exhaust's job is to keep the car quiet, so with the Magnaflow you're just hearing more of what was there all along. But that should only happen on lift-off throttle conditions...
I have a Flowmaster 40 with no issues. Just the burble when I let off....

 

Yeah that's what it sounds like - actually thats quite an accurate description.

 

I think you're fine. When I get a chance, I'll record it and send it to you so you can hear it...
Send me a PM with your email if you want...

 

http://video.google.com/videoplay?do...06073364&hl=en

Here's my vid of it... sorry for no visual but yeah you can hear the backfiring a bit (i took this for another purpose)

 

Hmmm. That was interesting. Your "burble" also occurs DURING throttle application. My car only does it when you lift-off.
Any shaking, missing or CEL's?

 

No CEL's, there is shaking between 700-1000 RPM during idle which is, i believe, my flywheel being a bit unbalanced (new flywheel installed 5K miles ago). There is also slight shaking during acceleration (mid to hard) which feels as if wheels are a wee bit unbalanced.

I don't know if there is any missing as there are no CELs, but I got new plugs and coils with 60K on them from a 95 waitin to be installed when i do my 90K service.

 

Bump for Sounbwoy haha

 

Sorry man. Work awaits. But may be you should go ahead and do your coils and plugs and get it over with? Not sure what else to tell you, but you def have a misfire; at least that what it sounds like to me...