i need some advice things havnt worked out as easy as planned, i went down to my local exhaust place today to get the cats took out and replaced with straight thru pipe now he says u cant use straight thru pipe cos theres this lambda sensor there and if the sensor is bypassed for example he said it will run like a bag ov shit is this correct.

i also was gonna get the small silencers removed to for that bit extra noise the silencers slightly behind the cats he said if i take them out it wont make any difference to noise im sick like i was lookin forward to it all been done somethings just dont happen like.

 

my car is a 1990 NA.

 

Any advice would be appreciated,

 

Thanks Phil.

i don't think my sensors are connected do they look like a threated screws with a long thing sticking out the middle ive got two of them one each side just hanging down so i tucked them out the way if there not Lambda Sensors i don't know what they are.

i never actually had them out but when it was on the ramp i seen 1 dont think there was one on the other side he showed me wot they look like threaded wid summat on the end and a wire on the other i think it was screwed into the cat like he says it controls the injection and will mess the fuelling up if i fiddle about wid them.

i never actually had them out but when it was on the ramp i seen 1 dont think there was one on the other side he showed me wot they look like threaded wid summat on the end and a wire on the other i think it was screwed into the cat like he says it controls the injection and will mess the fuelling up if i fiddle about wid them.

 

That will be your CAT warning light sensor , your 02 sensors are in the manifold so unless you are removing this then you have no problem , I would think about taking it to another garage :( :rolleyes:

so i think i should think about having them put back in or somthing then.

 

Phil300zx i've seen some where a straight through pipe with holes in possibly for these sensors i think it was specialistZ. but people do have straight through pipes so it can be done try Luke at the Zcentre he sells them for £180, he should be able to advice you about the sensors.

ok cheers guys for that cheers jaffa.

so i think i should think about having them put back in or somthing then.

 

Phil300zx i've seen some where a straight through pipe with holes in possibly for these sensors i think it was specialistZ. but people do have straight through pipes so it can be done try Luke at the Zcentre he sells them for £180, he should be able to advice you about the sensors.

 

JAFFA !!!!!!!!!!!!!!!!!!!! the 02 sensors are before the cat/decat pipes , when decatting you do not need to concern yourself with the 02 sensors as your going no where near them

 

Ryan

That will be your CAT warning light sensor , your 02 sensors are in the manifold so unless you are removing this then you have no problem , I would think about taking it to another garage :( :rolleyes:

 

 

 

so its def only a warning sensor and hes fobbed me off hes that type like he was adament it would upset the fuelling if i took it out like.

& usually the cat temp sensors are tied up out of the way

That will be your CAT warning light sensor , your 02 sensors are in the manifold so unless you are removing this then you have no problem , I would think about taking it to another garage :( :rolleyes:

 

 

sorry to go on lol so if i replaced it wid a bit ov straight thru pipe it wudnt harm it.

so its def only a warning sensor and hes fobbed me off hes that type like he was adament it would upset the fuelling if i took it out like.

 

Well he would be right if they were 02 sensors but there not :rolleyes: :)

sorry to go on lol so if i replaced it wid a bit ov straight thru pipe it wudnt harm it.

 

Correct :smw:

Well he would be right if they were 02 sensors but there not :rolleyes: :)

 

 

 

ok thanks any suggestions how to get a bit more noise i was thinking ov the boixes underneath but he says no which only leaves me wid back boxes.

Phil, you can cut those sensors off (they go up through the floor to a black box, which sits under the centre console behind the handbrake, you can remove that too if you like.) You can also take the exhaust further than that by taking out the AIVs (when you are under the car, just in front of the cats there are pipes coming out of the exhaust (one each leg) which join into rubber pipes, you dont need those either and it make sa tidier job of it. None of the above will negatively affect the performance of your car. I have run a 90 jap spec NA for a year with both removed and, until I starteed to break it for parts, it was the most powerful NA on this forum.

 

As for noise , if he knows his stuff he can tune the pipe. But by the time you have taken the cats out and less restrictive back boxes, it will sound a lot better anyway

Phil, you can cut those sensors off (they go up through the floor to a black box, which sits under the centre console behind the handbrake, you can remove that too if you like.) You can also take the exhaust further than that by taking out the AIVs (when you are under the car, just in front of the cats there are pipes coming out of the exhaust (one each leg) which join into rubber pipes, you dont need those either and it make sa tidier job of it. None of the above will negatively affect the performance of your car. I have run a 90 jap spec NA for a year with both removed and, until I starteed to break it for parts, it was the most powerful NA on this forum.

 

As for noise , if he knows his stuff he can tune the pipe. But by the time you have taken the cats out and less restrictive back boxes, it will sound a lot better anyway

 

 

ok thanks he says the boxes underneath wont make a difference to sound level so i was thinking ov doing away wid the back boxes altogether do you think this wud improve her sound a little bit or do u think it is hardly worth it.

Thanks Baggins, but surely if my O2 sensors are not connected this may mean i already have straight through pipes, but she don't seem that loud just a nice purr i'll have to have a look underneath for some cats.

Thanks Baggins, but surely if my O2 sensors are not connected this may mean i already have straight through pipes, but she don't seem that loud just a nice purr i'll have to have a look underneath for some cats.

 

OK LISTEN!!!!!!!!!!!!!!!!!

 

Your 02 sensors are NOT in your cats or de-cat pipes they are in the exhaust manifold which is completelly seperate, if your 02 sensors are not connected the car would run like a bag of shite!!!!!!!!!!!!!

 

Ryan

Oh right, i get ya,

 

sorry about being a dumb arse but i don't do the mechanical side.

ok thanks he says the boxes underneath wont make a difference to sound level so i was thinking ov doing away wid the back boxes altogether do you think this wud improve her sound a little bit or do u think it is hardly worth it.

 

Do not remove all the silencers and back boxes. The noise will be so ear deafening loud you'll end up putting the lot back in no time ;) Can't remember who it was but they removed the silencers and had the back pipes straight out without the benefit of a back box and when stationary the dB noise level was illegal and at motorway speeds it was unbearably loud. It also set off car alarms all over the place. Guy had it in that state for under a week and put the lot back - much happier chappy now and not being threatened with Anti-Social Behaviour Orders! LOL

Do not remove all the silencers and back boxes. The noise will be so ear deafening loud you'll end up putting the lot back in no time ;) Can't remember who it was but they removed the silencers and had the back pipes straight out without the benefit of a back box and when stationary the dB noise level was illegal and at motorway speeds it was unbearably loud. It also set off car alarms all over the place. Guy had it in that state for under a week and put the lot back - much happier chappy now and not being threatened with Anti-Social Behaviour Orders! LOL

 

 

lmao was only thinking ov the back boxes so you reckon it wwill be loud lol.

one more question lol there seems to be some little pipes shootin off the cat not sure wot these are for.

one more question lol there seems to be some little pipes shootin off the cat not sure wot these are for.

 

Re-read Jocks post on page one

ok any suggestions wot these gets do.

They are the anti-smog pumps :p No, seriously they are!!! AKA AIVs. Basically just more junk thrown on the car for Californias whiter than white emissions laws... Not needed and more likely to sound like drinking from a McDonalds cup....