Post LT header install header issues

**ob02z28** · 02-12-2010, 10:13 AM

I just installed BBK long tube headers and y pipe, really woke the motor up, but I have two issues; (1) right side header vibration during idle ONLY, and (2) check engine soon light is on. Feedback please.

**mpfranks** · 02-12-2010, 10:43 AM

Originally Posted by ob02z28

I just installed BBK long tube headers and y pipe, really woke the motor up, but I have two issues; (1) right side header vibration during idle ONLY, and (2) check engine soon light is on. Feedback please.

are you running cats? if not, then the rear o2's will set off ses light. need o2 sims or tuned out.

and check to see if the right side is hitting the control arm mount.

**WS6 > SS** · 02-12-2010, 12:31 PM

x2 on the rear o2 sensors.

**pajeff02** · 02-12-2010, 12:41 PM

Any chance you have a heat shield vibrating? After installing our catback, the rear heatshield just in front of the axle picked up a resonate vibration.

**JoshuaGrooms83** · 02-13-2010, 05:13 PM

Question on the cat subject of this thread, would cats solve the ses light? High flow cats to be exact?

**0verkill** · 02-13-2010, 05:20 PM

i dont think so its best to just get a tune. frost can get you done for $125. your car is rich now from the install and you will get more out of them with the tune.

**mpfranks** · 02-13-2010, 05:24 PM

if you run cats and keep the rear o2's your light should go out.

**BlackSS1** · 02-14-2010, 06:00 AM

Originally Posted by mpfranks

if you run cats and keep the rear o2's your light should go out.

HI flow cats don't solve the SES light (ask me how I know). They just don't clean air as well as stock cats. You will need a tune to tune out the rear O2 sensors. Good thing is the tune can net a few more HP too.

**JoshuaGrooms83** · 02-14-2010, 07:50 AM

So even if you get new cats and still keep the rear o2's it still will throw codes then? So as long as the PCM is retuned and you dont have to pass a visual emissions, your fine then? (not a cali resident)

**BlackSS1** · 02-14-2010, 03:42 PM

Yes, if you don't have a visual and they don't freak at the no-cat smell of the car, you should be fine. A tune can make it pass OBD II inspection no problem.

**JoshuaGrooms83** · 02-14-2010, 04:14 PM

cool. So ill just for go the cats and get the tune alone then

**bbuikema** · 02-14-2010, 04:32 PM

Originally Posted by BlackSS1

Yes, if you don't have a visual and they don't freak at the no-cat smell of the car, you should be fine. A tune can make it pass OBD II inspection no problem.

Are you sure that if you tune out the rear O2s, it will still pass the ODB II inspection. I always assumed the test would fail since your car is no no longer reporting that is has rear 02s.

**BlackSS1** · 02-14-2010, 04:57 PM

Originally Posted by bbuikema

Are you sure that if you tune out the rear O2s, it will still pass the ODB II inspection. I always assumed the test would fail since your car is no no longer reporting that is has rear 02s.

Yup, decent tuners know how to do this. They eliminate the trouble codes from reporting errors for the disabled or failing emissions equipment such as rear O2s. The readiness monitors still report as ready so it appears you have rear O2s still. But no trouble codes appear for whatever is tuned out, and your car passes emissions. Pretty trick stuff!

Hit up Frost site sponsor, he can hook you up with a tune or find a reputable local GM tuner.

**bbuikema** · 02-14-2010, 05:22 PM

Originally Posted by BlackSS1

Yup, decent tuners know how to do this. They eliminate the trouble codes from reporting errors for the disabled or failing emissions equipment such as rear O2s. The readiness monitors still report as ready so it appears you have rear O2s still. But no trouble codes appear for whatever is tuned out, and your car passes emissions. Pretty trick stuff!

Hit up Frost site sponsor, he can hook you up with a tune or find a reputable local GM tuner.

Cool, I actually have HP tuners and am in the process of putting in Kooks headers and ORY. I was trying to figure out if just tuning out the O2s would work or if I needed to get a catted Y to put in when I get my emissions test, then put the ORY back in afterwords.

**JoshuaGrooms83** · 02-14-2010, 07:47 PM

So If I add highflow cats in and still delete the rear o2s out, the cats still burn the unspent fuel?

**BlackSS1** · 02-16-2010, 01:56 AM

Yes the hiflow cats still work fine whether you have rear O2s or not. The rear O2s only monitor the effectiveness of the cats.

You need to have cats if you have a visual inspection, although they are moved from stock location so technically they are illegal anyways. I chose to have a catted Y to cut down on noise and fumes, but it is your choice based on those considerations.

**LS1_ws6** · 02-16-2010, 08:19 AM

The OBD II code for this is P0153 right?

**jsremmos** · 02-17-2010, 06:30 PM

your vibrations are from the primary tube being pressed against the k-member. happends all the time. just notch it

**JoshuaGrooms83** · 02-18-2010, 07:44 AM

so the $37 highflow cats off ebay would be fine to add? All they gotta do is cut down on some of the unburnt fuel and smooth out the exhaust note a bit right?