Intake issues

**Ieatstangs** · 08-06-2012, 08:05 PM

Does my 98 z28 a4 need a tune to compensate for a bbk intake my mods are the intake a lid Macs with a x. Pipe rear o2 sims .... jus did thr plugs and wires the Pcv is custom and all there keeps throwing lean codes and a iac code randomly but iac is new

The fuel filter is new the fuel pressure is fine no vaccum leaks I'm kinda stumped never had the issue with the stock intake I can feel a slight difference but it's not worth burning up my pistons

Any help would be beneficial

Should I put the stock back on until I can get a proper tune ?

**2002ssslp** · 08-06-2012, 10:14 PM

In one simple word YES ! Send the pcm to Steve at Frost and have it tuned right.

**SuperSSguy** · 08-07-2012, 12:08 AM

Originally Posted by Ieatstangs

Does my 98 z28 a4 need a tune to compensate for a bbk intake my mods are the intake a lid Macs with a x. Pipe rear o2 sims .... jus did thr plugs and wires the Pcv is custom and all there keeps throwing lean codes and a iac code randomly but iac is new

The fuel filter is new the fuel pressure is fine no vaccum leaks I'm kinda stumped never had the issue with the stock intake I can feel a slight difference but it's not worth burning up my pistons

Any help would be beneficial

Should I put the stock back on until I can get a proper tune ?

Agree with 2002ssslp...but what lean codes is it throwing?....what numbers?

**pajeff02** · 08-07-2012, 02:56 AM

Any time you install new components that alter the air flow through the engine its volumetric efficiency (VE) changes. Within the tune, there is a VE table that should reflect the engine's actual VE and this, among other things that can be done in a tune, is what needs modified. Granted, the combination of the MAF, MAP and closed loop operation utilizing O2 sensor data can compensate for the changes to some extent, however it still needs a tune to run properly and to realize the greatest gains from your new parts. I have heard of intake leak issues with the BBK unit, so you may want to really check it carefully for a vacuum leak. If you need some testing options, let us know. Also, as requested, please post your codes.

**Ieatstangs** · 08-07-2012, 09:10 AM

I can't remember the number but they were for lean bank 1 and 2 sometimes it's both other times it's jus bank 1 .....pAjeff where should I look for vaccum leaks ?

**nathanWS6** · 08-07-2012, 02:26 PM

sounds like a slight leak in intake.. while you will gain HP by getting a tune to maximize preformance I don't think it's 100% needed.. just switching out the intake would not cause lean conditions especially since the BBK doesn't flow alot more than stock or an LS6..

**cammed goat** · 08-07-2012, 03:55 PM

P0175 or 176?

**pajeff02** · 08-07-2012, 05:28 PM

Leaks were at the intake seals against the heads, if I recall correctly. I'll see if I can find the thread I was thinking of.

**pajeff02** · 08-07-2012, 05:38 PM

Ok, found the thread. Looks like the OP there had issues with the intake not setting down against the heads. Apparently, the clips on the knock sensor harness have to removed and there may have been an issue with the coolant air bleed tubes. He also re-used his stock o-rings which is never a good idea.

**Ieatstangs** · 08-07-2012, 06:23 PM

Originally Posted by pajeff02

Ok, found the thread. Looks like the OP there had issues with the intake not setting down against the heads. Apparently, the clips on the knock sensor harness have to removed and there may have been an issue with the coolant air bleed tubes. He also re-used his stock o-rings which is never a good idea.

I'm confused what does this mean?

I replaced my engine cover bolt with a hex bolt as the instructions said

I want to take it off n double check but I have to get another set of gaskets ..,

***SMWS6TA*** · 08-08-2012, 12:03 PM

Blindly guessing he is referring to the valley cover tray bolts. They sit up quite a bit.

Are you using the LS1 coolant tubes or LS6 coolant bypass?

I'm waiting on a buddy that has a BBK intake to get back with me on how he did his.

**Ieatstangs** · 08-08-2012, 12:15 PM

I'm using the stock ls1 coolant tubes that's kinda why i went bbk ( and it was free lol) but I figured there was nothing needed

**Ieatstangs** · 08-22-2012, 06:04 PM

Ok I got it tuned and it came back so I checked fuel pressure and it's good ... We found a leak near the front of the intake ..It seems to be sitting up a lil on the front coolant tube .should I change the coolant pipe ? and or who has the best kit thanks in advance I saw Texas speed has one