Why is my car slow and running rich

[zach44102]

At WOT by the time im at 6800rpm im 10:1 AFR. New o2 sensors and it was not like this with a open y pipe. With a open y pipe and no catback the car pulled really hard up high. And AFR's were steady and moderate. Inform me, what do i do? Help me not rip off my new 2.5" catback.

 

[RonPorter]

I'm wading into unfamiliar territory here, but I thought that rich (maybe 11-ish) wasn't a bad thing at high rpms??

 

[Ishodu]

The open Y pipe would likely give you false readings. Plain and simple your car needs tune.

 

[zach44102]

I dont see why it would give me false readings? I dont see why it would. Im still getting a pinging sound too. Next time i get gas im going to throw 93 in it to see if that helps. Can a AFR be effected by the PCM pulling timing?

 

[zblackbeast]

Well, I just found out that an exhaust leak near the o2s could cause the sensors to read lean.. and since you is running rich, that MASSIVE exhaust leak you have there could have tricked the sensors into reading correct oddly enough?!?! (My wild theory anyway)

 

[zach44102]

I dont have a exhaust leak though???? O and i just reset the PCM disconected the battery for a hour. Maybe it will fix itself.

 

[rubydist]

check the codes after driving for a day or two and let us know what you find.

 

[zblackbeast]

Exhaust leak being you had no cat back

 

[yamahaSHO]

I'm wading into unfamiliar territory here, but I thought that rich (maybe 11-ish) wasn't a bad thing at high rpms??

11:1 is turbo Subaru territory for WOT, but an NA SHO should be targeting for 13:1. I'm curious as to what his ECU is commanding as the stock ECU does dip very rich. I command 12:1 on my SC SHO.

The open Y pipe would likely give you false readings. Plain and simple your car needs tune.

An open Y-pipe will not give you false readings unless your WBO2 is mounted near the end of the pipe.

Exhaust leak being you had no cat back

That's not a leak.

 

[zach44102]

I reset the computer by disconecting the battery for a awhile. Ran a little better. 11.5:1 at WOT. I need i tune bad i guess

 

[zblackbeast]

Eh, it was a thought..

And Zach, I thought your wideband was near the tail section of the y-pipe, no?

 

[zach44102]

No, its in the front bank. In the y pipe.

 

[NotSoSlowSHO]

you need a tune.

 

[intimdatr]

Dont you have a tuner with Data logging? why not hook it up load a stock tune and see whats going on?

 

[zach44102]

Car is running in the 10:1 AfR by 6500 rpm. Cleaned the MAF put in new o2 sensors. No change. Still
Getting spark knock on light load aroud 2500-3000rpm. And it does go away when i pull the spout and manually set timing at 10*