420a Running Extremely Rich:

[geekyguru]

I have dont some exhaust work, as well as intake work.
I have to hold the accelerator in to start, and when it does start.. it spits out some smoke, and takes forever to stabilize an idle. I also have a UDP on, but i know its running real rich..
any tips on getting this fixed?

 

[top_end95]

Problem Diagnosis

 

[Doug99RS]

Your information you gave is really vague. What kind of exhaust and intake work have you done? What's the history on the plugs, wires, maintenance, when did the problem start? Did it start after any mods were done? Do you have a check engine light on after it starts running? When was the last time you cleaned the throttle body?
Doug

 

[MitzEclipse]

Have the same problem here too... idk if im running lean or rich.... i do have a air fuel ratio gauge, but its not working because one of my o2 sensor broke.....


I have full header, greddy evo exhaust, no cat and cold air intake and when i redline 3rd into 4th as soon as i shift i shoot a fire ball ...... then when im doing 115... in 4th and i let go of the gas it pops like crazy and my friends tell me that is insane how it just shoots fire and the sound is just so beautiful...... gotta give it to those greddy tech's ... mofo know how to make stuff sound great.... anyways can anyone tell me why im shooting fire?

 

[Doug99RS]

Not having a catalytic converter will do this because it's designed to release oxygen to match the unburned fuel. When the oxygen is released the fuel and oxygen finish burning off creating lower emissions. Doing away with the cat with keep the exhaust richer than normal and will cause both a deeper exhaust as well as flames shooting out of the back during shifts.

You need to fix your o2 other wise your exhaust may be slightly richer due to the missing cat but your engine could be very lean causing it to run too hot and burn the valves. When I say too hot I don't mean coolant temp I mean the burn temps in the combustion chamber. Fix the o2 before you damage something.
Doug