Lift not engaging properly

[Jay123]

 

Hi everyone,

I am having a problem with my 03 Corolla Sportivo. 

The car previously has a cat-back custom exhaust that would engage lift strongly and prominently. 

I did not like how loud it was so I took it back (around a year later) to replace the resonator and install a quieter muffler.

Since then I have noticed that lift does not engage anywhere nearly as significantly as before (almost no noticeable power increase) and sounds like it is struggling in the higher rev range/ not operating smoothly. 

I notice at 6k rpm the engine will cut off very briefly and then continue onward to redline, same sort of sound and feel between on/off lift.

I am wondering if this might actually be an issue or it is just all in my head going from loud to quiet. 

 

[Hiro]

Have the lift bolts been replaced?

[Squalled]

How many kms has it clocked so far? Other than lift bolts, the OCV and lift filters could be clogged, if it's had poor service history or even high kms.

What size exhaust were you running prior to going stock? Could always be a restriction that makes the lift transition not seem as strong.

I know this after going from Injen intake to stock, it felt quiet restricted between 6500-7800, felt flat.

[Jay123]

On 12/09/2018 at 3:57 PM, Hiro said:

Have the lift bolts been replaced?

Hi Hiro, 

Thanks for the reply. 

I had done a bit of research since then and checked the lift bolts for any sign of breakage. 

They both appear to be fully intact, so the next step might be the OCV/lift filters.

12 hours ago, Squalled said:

How many kms has it clocked so far? Other than lift bolts, the OCV and lift filters could be clogged, if it's had poor service history or even high kms.

What size exhaust were you running prior to going stock? Could always be a restriction that makes the lift transition not seem as strong.

I know this after going from Injen intake to stock, it felt quiet restricted between 6500-7800, felt flat.

Hi Squalled,

It is currently sitting on 272, xxx kms. I will try to check the OCV and lift filters once I have a bit of time tomorrow and from my knowledge, the service history is up to date. 

the exhaust is a 2 1/4 inch and remains the same width as before, just with a longer resonator and different muffler. 

I was previously running a CAI and went from stock as well but that didn't seem to affect performance in any way in terms of the transition to lift. 

I will try and record and upload some videos of acceleration to see if that might be helpful in diagnosing. 

[Jay123]

Update.. 

I pulled apart the lift screen and it all seems to be in order and no signs of blockage, however, I am concerned at the oil colouration (was only changed 5000km ago). 

I guess the next step might be to take it back to the exhaust shop and see what they think?

 

Let me know what you think

[Squalled]

The oil colour looks pretty dark.

When you go full throttle do you notice any smoke at all? What viscosity oil are you using? Lift requires a few elements for it to engage correctly.

[Jay123]

20 hours ago, Squalled said:

The oil colour looks pretty dark.

When you go full throttle do you notice any smoke at all? What viscosity oil are you using? Lift requires a few elements for it to engage correctly.

I think so too.. 
I don't notice any smoke in the mirrors although it might be worth noting when the engine is warming up there is frequent pops and burbles (not really noticeable now due to quiet muffler) up until operating temp.

sadly I don't know what viscosity is currently inside the engine as I usually take it to the mechanic for things like oil changes. 

[Squalled]

6 hours ago, Jay123 said:

I think so too.. 
I don't notice any smoke in the mirrors although it might be worth noting when the engine is warming up there is frequent pops and burbles (not really noticeable now due to quiet muffler) up until operating temp.

sadly I don't know what viscosity is currently inside the engine as I usually take it to the mechanic for things like oil changes. 

The pops and burbles, is that while driving or idling? Most will do that when driving cold.

[Jay123]

Update:

 

I completed a full oil change using 10w30 oil and still no difference engaging lift. 

I think it must come down to the exhaust being very restrictive, should I revert back to the old setup? Sucks because I was enjoying the peace and quiet! 😁

[Squalled]

On 9/15/2018 at 7:42 PM, Jay123 said:

Update:

 

I completed a full oil change using 10w30 oil and still no difference engaging lift. 

I think it must come down to the exhaust being very restrictive, should I revert back to the old setup? Sucks because I was enjoying the peace and quiet! 😁

The exhaust shouldn't stop lift from engaging. I've seen quite a few owners revert from a modified system back to a standard one without any issues engaging lift. 

Are there any loose wires and are all plugs connected?

[Jay123]

On 9/17/2018 at 9:08 AM, Squalled said:

The exhaust shouldn't stop lift from engaging. I've seen quite a few owners revert from a modified system back to a standard one without any issues engaging lift. 

Are there any loose wires and are all plugs connected?

Hi there, 

Sorry for leaving this thread suddenly, just wanted to give an update on the situation. 

I unbolted the exhaust from the headers a while back and.. 

Although the car was obnoxiously loud, I took it for a drive and it was as powerful as ever, lift engaged properly and felt pretty quick, even quicker than when I had the other exhaust on. 

I think it must be plugged somewhere between the cat through to the muffler or simply just too small/restrictive to flow effectively. 

Do you have any suggestions on how I can fix this or can I only solve it by getting a new exhaust made specifically for my car?

[Squalled]

On 11/9/2018 at 6:47 PM, Jay123 said:

Hi there, 

Sorry for leaving this thread suddenly, just wanted to give an update on the situation. 

I unbolted the exhaust from the headers a while back and.. 

Although the car was obnoxiously loud, I took it for a drive and it was as powerful as ever, lift engaged properly and felt pretty quick, even quicker than when I had the other exhaust on. 

I think it must be plugged somewhere between the cat through to the muffler or simply just too small/restrictive to flow effectively. 

Do you have any suggestions on how I can fix this or can I only solve it by getting a new exhaust made specifically for my car?

What catalytic converter do you run? It's possible that the cat could be blocked somewhere, which happens sometimes.

The stock muffler is quite restrictive so unless the aftermarket is even more restricted, I'd rule it out.

[Jay123]

On 11/12/2018 at 10:51 AM, Squalled said:

What catalytic converter do you run? It's possible that the cat could be blocked somewhere, which happens sometimes.

The stock muffler is quite restrictive so unless the aftermarket is even more restricted, I'd rule it out.

I think it is the stock cat welded on. 

Is there any way to test for blockages or do I have to completely remove it?

Edited November 13, 2018 by Jay123
Wrong information

[Squalled]

16 hours ago, Jay123 said:

I think it is the stock cat welded on. 

Is there any way to test for blockages or do I have to completely remove it?

https://axleaddict.com/auto-repair/How-to-Test-a-Bad-Catalytic-Converter this may help with diagnosis.

I've never had to diagnose one before so it would be to check elsewhere online in case. You don't have any check engine lights or anything right? Also how's you O2 sensor?