Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers

[HiLex]

Thorley Headers and Engine codes

I have had my headers on since March and have been very happy with them. I did have the P0420 and P0430 codes showing up I still have all 4 cats but the flowmaster high flow cats. From searching the forums I am surmising that the intake headers highflow cats and Cat back exhaust has increased the exhaust gas flow which screws with the O2 sensors. I was going to get the URD kit but they were back ordered so I saw where other people had good results by placing O2 sensor spacers on the rear sensors. I found them on Amazon and figured for the price it was worth a try 2 months later no codes and it runs fine. I no longer need the URD kit and now that the spacers have heat discoloration they are not noticeable when looking under the vehicle.

http://www.amazon.com/Blox-Racing-B...2 spacers&qid=1463763753&ref_=sr_1_11&sr=8-11

 

[t-man]

URD simulator will keep lights and codes away. Original or aftermarket cat will keep inspectors happy.
As far as I know the only state that may have an issue with headers is California, but... If you are hooking up a legal exhaust system, ie: cats, muffler, etc, then it shouldn't be a problem. The headers even keep the air injection system in tact so they can't even ***** about that. Check with local inspectors first of course, but all these do is replace the faulty manifolds.
If I lived in a ***** state like that I would have a nice exhaust made with a flange before the cats. I'd pass inspection then unbolt it and bolt in my real exhaust, no cats and loud ass muffler!

 

[sr3tlaw]

URD simulator will keep lights and codes away. Original or aftermarket cat will keep inspectors happy.
As far as I know the only state that may have an issue with headers is California, but... If you are hooking up a legal exhaust system, ie: cats, muffler, etc, then it shouldn't be a problem. The headers even keep the air injection system in tact so they can't even ***** about that. Check with local inspectors first of course, but all these do is replace the faulty manifolds.
If I lived in a ***** state like that I would have a nice exhaust made with a flange before the cats. I'd pass inspection then unbolt it and bolt in my real exhaust, no cats and loud ass muffler!

Do it once; do it right. That's what I hear. All matter of preference. I like [MENTION=101553]t-man[/MENTION] style

Sent from my XT1575 using Tapatalk

 

[Jason B]

I completely disagree.
The header itself will be a cleaner burning/flowing experience for your engine.

If you have installed the DT (or any other custom header), but retained all the other emissions equipment (cats and sensors), you will pass the emissions test. What you will fail is the visual inspection. Unless your smog guy is vision impaired :noidea:

Correct. You will actually have a MUCH CLEANER burning vehicle in CA. DT is working and planning to get them certified carb legal in CA, but it just takes time....

Doug Thorley 03-04 headers ORDER LINK

Doug Thorley 05-09 headers ORDER LINK

ALSO, I CAN THE MAGNAFLOW/FLOWMASTER CATS/MUFFLERS for anyone at great prices

Call/text me at 717-319-2100 to order over the phone, or to order online with a Credit Card, click below

 

[zidaro]

URD simulator will keep lights and codes away. Original or aftermarket cat will keep inspectors happy.
As far as I know the only state that may have an issue with headers is California, but... If you are hooking up a legal exhaust system, ie: cats, muffler, etc, then it shouldn't be a problem. The headers even keep the air injection system in tact so they can't even ***** about that. Check with local inspectors first of course, but all these do is replace the faulty manifolds.
If I lived in a ***** state like that I would have a nice exhaust made with a flange before the cats. I'd pass inspection then unbolt it and bolt in my real exhaust, no cats and loud ass muffler!

Lots of hoops to jump thru here in the Sunshine State! but all the pretty girls are worth it :banana:
Where theres a will, theres a way! thats what i say :art:

 

[Jason B]

Lots of hoops to jump thru here in the Sunshine State! but all the pretty girls are worth it :banana:
Where theres a will, theres a way! thats what i say :art:

Evidently, not so bad now. A customer of mine just got back to me with this to fix any codes!

Amazon.com: Blox Racing BXFL-00108 Check Engine Light Eliminator Adapter: Automotive

It moves the rear sensor out of the gas flow. He's had it installed for a couple of months, and no problems. He was trying to save some money and it worked. He ordered 2.

 

[t-man]

Evidently, not so bad now. A customer of mine just got back to me with this to fix any codes!

Amazon.com: Blox Racing BXFL-00108 Check Engine Light Eliminator Adapter: Automotive

It moves the rear sensor out of the gas flow. He's had it installed for a couple of months, and no problems. He was trying to save some money and it worked. He ordered 2.

Only works of you have the cats still. I tried it on my truck, no Bueno.

 

[Jason B]

Most keep at least 2 cats, right?

 

[HiLex]

O2 Spacer

True it only works if you have the cats installed and Yes Colorado does a visual and tailpipe test which I have passed with the spacers installed. It is cheaper than the URD kit and works fine it's it is all about personal preference. I would rather use the $150 towards a Unichip piggyback tuner than the URD.

 

[HiLex]

Yes Jason you Should at least have the front cats installed to use the O2 spacers.

 

[tmcintosh3]

I completely disagree.
The header itself will be a cleaner burning/flowing experience for your engine.
The URD harness will prevent codes from being thrown and will prevent the dash from lighting up.
If you have installed the DT (or any other custom header), but retained all the other emissions equipment (cats and sensors), you will pass the emissions test. What you will fail is the visual inspection. Unless your smog guy is vision impaired :noidea:

Ok, now I am a bit confused. I know DT headers cannot be shipped to a California address (a non issue really).

If I were to install DT headers, but keep street/CA legal cat and muffler, I would still pass CA smog?

Anyone out there in California that has DT headers and has passed smog? Can anyone clarify or confirm?

Thanks!

 

[groverdill]

Picked up my 05. THE TICK IS GONE!!!

It sounds good with the 2.25" into 3" super 70 flowmaster, it is not over bearing it is nice and mellow and sounds like it should have from the factory.

I will put it up on the lift this weekend and get some pics if I have time.

I am super happy with the results.

 

[zidaro]

Ok, now I am a bit confused. I know DT headers cannot be shipped to a California address (a non issue really).

If I were to install DT headers, but keep street/CA legal cat and muffler, I would still pass CA smog?

Anyone out there in California that has DT headers and has passed smog? Can anyone clarify or confirm?

Thanks!

I have not put my headers in yet, and don't have smog in my County after Title changes, so i won't be able to tell you positive.

this i can tell you-
With the DT headers installed with all your other OEM equipment, it will pass the emissions portion. If your sensors are not lighting up the dash.
What it will not pass, legally, is the visual. "sometimes" if you "know someone" you might get thru.

of course, I'm no CARB expert, so take it all with a grain of salt.

 

[Jason B]

What it will not pass, legally, is the visual. "sometimes" if you "know someone" you might get thru.

So, if you know someone at a shop, they could put it through? Like here in PA, tinted front windows aren't allowed, but if you know someone, they will pass it.

Doug Thorley 03-04 headers ORDER LINK

Doug Thorley 05-09 headers ORDER LINK

ALSO, I CAN THE MAGNAFLOW/FLOWMASTER CATS/MUFFLERS for anyone at great prices

Call/text me at 717-319-2100 to order over the phone, or to order online with a Credit Card, click below

 

[Jagerzel]

Cats vs no cats

Is there any real benefit to just removing the cats after the headers vice putting in the highflow magnums? My largest concern is that I want the vehicle as stock quiet as possible especially in the cabin. Thanks! (and I have no inspections in my state)

On another note 15 out of 16 studs removed. One left that is refusing to budge so we shall see. Advice do not be on the wrong side of the 3ft pipe breaker bar or your face will result in you telling everyone at work the first rule of fight club.

 

[SSt4r]

I have had my headers on since March and have been very happy with them. I did have the P0420 and P0430 codes showing up I still have all 4 cats but the flowmaster high flow cats. From searching the forums I am surmising that the intake headers highflow cats and Cat back exhaust has increased the exhaust gas flow which screws with the O2 sensors. I was going to get the URD kit but they were back ordered so I saw where other people had good results by placing O2 sensor spacers on the rear sensors. I found them on Amazon and figured for the price it was worth a try 2 months later no codes and it runs fine. I no longer need the URD kit and now that the spacers have heat discoloration they are not noticeable when looking under the vehicle.

Amazon.com: Blox Racing BXFL-00108 Check Engine Light Eliminator Adapter: Automotive

I'll recommend these as well I had ruined my cats and was getting these codes BEFORE my DT install. New O2 sensor didn't work. New A/F sensor didn't work. Installed these and no more codes before or AFTER DT install.

 

[t-man]

Is there any real benefit to just removing the cats after the headers vice putting in the highflow magnums? My largest concern is that I want the vehicle as stock quiet as possible especially in the cabin. Thanks! (and I have no inspections in my state)

On another note 15 out of 16 studs removed. One left that is refusing to budge so we shall see. Advice do not be on the wrong side of the 3ft pipe breaker bar or your face will result in you telling everyone at work the first rule of fight club.

You will be louder without the cats and also get a cel light which will only go away with the URD O2 simulator. You also won't pass inspection if you have that in your state.

 

[Jagerzel]

Thanks!

You will be louder without the cats and also get a cel light which will only go away with the URD O2 simulator. You also won't pass inspection if you have that in your state.

Thanks for the reply, I'm ordering up the cats now. Finally got the headers off with only one stuck nut which had to be dremeled off with a grinder wheel so now gotta weld another nut to the stub and get the bolt out. This has been a hard task, but not 2000$ task as I have been quoted one the DMV area.

 

[Jason B]

Thanks for the reply, I'm ordering up the cats now. Finally got the headers off with only one stuck nut which had to be dremeled off with a grinder wheel so now gotta weld another nut to the stub and get the bolt out. This has been a hard task, but not 2000$ task as I have been quoted one the DMV area.

I can get you maganflow or flowmaster cats cheap, and have them in stock.

 

[Jagerzel]

I can get you maganflow or flowmaster cats cheap, and have them in stock.

Pmed