EGR exhaust backpressure - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

miklos · 12-03-2009, 02:12 AM

I have a 1990 240sx. I was told by a smog tech that my exhaust doesn't have enough backpressure to open the EGR at idle.

I have a large cat--not high flow and a coffee can muffler with a silencer in the tip.

The tech said I would lower NOX by getting the EGR to work with more backpressure.

Should I add a resonator to increase the pressure?

sil80 monster · 12-03-2009, 02:35 AM

put high octane gas in and make sure your CAT is HOT....worked for me

miklos · 12-04-2009, 12:30 AM

I added a resonator and the car has more power. Plus it is quieter. Going for a NOX test next.

Rabboni · 12-04-2009, 01:15 AM

Your egr shouldn't work at idle. the only way to properly test back pressure is to put the engine under load during the pressure test (i.e. on the dyno) and then see if i creates enough pressure. Easier way to test your egr it to apply vacuum to the egr valves signal port while the engine is at idle and listen for the engine speed to drop, or start sputtering, or die.

***S14DB*** · 12-04-2009, 01:33 AM

we just covered this. search....

http://zilvia.net/f/tech-talk/167571...aust-size.html

12-03-2009, 02:12 AM	#1
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 269 Trader Rating: (0) Feedback Score: 0 reviews	EGR exhaust backpressure I have a 1990 240sx. I was told by a smog tech that my exhaust doesn't have enough backpressure to open the EGR at idle. I have a large cat--not high flow and a coffee can muffler with a silencer in the tip. The tech said I would lower NOX by getting the EGR to work with more backpressure. Should I add a resonator to increase the pressure?

12-04-2009, 01:33 AM	#5
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	we just covered this. search.... http://zilvia.net/f/tech-talk/167571...aust-size.html __________________ Comments should be taken as Opinions not as Statements of Fact

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12-03-2009, 02:35 AM	#2
sil80 monster BANNED Join Date: Jun 2009 Location: chino hills, ca Age: 36 Posts: 312 Trader Rating: (5) Feedback Score: 5 reviews	put high octane gas in and make sure your CAT is HOT....worked for me

12-04-2009, 12:30 AM	#3
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 269 Trader Rating: (0) Feedback Score: 0 reviews	I added a resonator and the car has more power. Plus it is quieter. Going for a NOX test next.

12-04-2009, 01:15 AM	#4
Rabboni Zilvia Member Join Date: Aug 2009 Location: Fairfield, CA Posts: 230 Trader Rating: (0) Feedback Score: 0 reviews	Your egr shouldn't work at idle. the only way to properly test back pressure is to put the engine under load during the pressure test (i.e. on the dyno) and then see if i creates enough pressure. Easier way to test your egr it to apply vacuum to the egr valves signal port while the engine is at idle and listen for the engine speed to drop, or start sputtering, or die.