Hewitt Bypass Kit

I’m hoping someone out there has some insight..

I installed a 1st Gen Hewitt Bypass kit in my 05’ SR5 Tindra to clear a persistent P1448 code (SAIS pump stuck switching valve). I installed the kit with the block-off plates for the exhaust manifolds.

The kit cleared the P1448 code, but now I am getting a P0013 code (the upstream 02 sensor). I didn’t have time to deal with it myself, so a local shop had a look and decided to change out that very expensive sensor!

Almost as soon as I got the truck back, the CEL light came back on again, and the shop say they won’t look at the truck again with the bypass kit installed as they now believe that is the issue!

Any thoughts anyone had would be greatly appreciated.

Pete

 

First off @HewittTech01 has great customer support.

Second, P0013 is Bank 1 Exhaust “B” Camshaft Position Actuator Circuit/Open, not upstream O2. But on that topic, you should always buy Denso brand O2 sensors, and ideally replace upstream and downstream at the same time.

Third, I believe that's going to be the VVTi sensor on the passenger's side of the engine but don't quote me on that. You need to check the harness is connected firmly with no bent pins. I believe BubbaW points out the location here: https://www.tundras.com/threads/camshaft-position-sensor-a-bank-2.123418/#post-3162361

 

Hi Shifty,

Thanks for the speedy response.

I fired off an email to Hewitt Tech.

I’m confused on the code? These photos are the screen from my code reader..

 

You said the code was P0013 above.
Reader says P0031 is the code.

P0031 is the upstream O2 sensor on the driver side. It could still be throwing codes if (A) the shop installed the wrong O2 sensor part number, (B) they used any off-the-shelf brand instead of using Denso (OEM) brand and there's a compatibility issue, with electronics on these trucks sometimes they're picky on generics and O2 sensors are one of those parts, (C) the sensor they used is defective, which if it wasn't OEM quality, is a high likelihood, (D) there actually was no issue with the O2, but there's a problem with the O2 circuit or plug, like a pin is bent in the plug, a wire got nicked, or similar, or it could be something else entirely.

There's ample troubleshooting available in the Toyota FSM for P0031. I'd start by figuring out what the shop installed, or if they even replaced the sensor. Maybe they used a generic sensor, thus had to splice the wiring ... O2 circuits aren't always happy with wire splicing, and you should never use anything that requires cutting the O2 sensor circuit.

Anyway, not enough info here for me to help. We have no way to know what they installed. This is why I don't trust shops. You didn't give me enough info to really find the correct part or pricing, but new Denso brand part should've been $150 or less, sometimes as cheap as $45, and they shouldn't have charged you more than one hour of labor/shop time to replace.

Since the shop did the work to replace the sensor, but the code is still there, I'd be going back to the shop and raising hell, asking what they fucked up.

 

The shop is stupid, but the bypass kit is super easy to remove, take it back the shop and have the fix them fix O2 sensor and then put the bypass kit back on.

Or if you're handy, but the denso sensor off rock auto and replace it.

 

So I recently bought an off brand 25$ MAF off of eBay had some issues with fluctuating idles and whatnot everyone spinning their heads trying to diagnose my 01 tundra sr5 4.7l 2wd no one seems to be able to come up with a fix or a cause of the issues so It’s like hit or miss throw money at your truck and see if what ya did makes a difference is all ya can do with the first gen yotas

 

General rule of thumb: Always use OEM brand for any electronic items related to ignition/combustion (air/fuel/spark). And don’t buy parts off fleaBay/scAmazon. Hitachi is the OEM brand for 1st Gen MAF on the V8. FSM has a process for testing MAF for resistance to confirm operation. This and plenty of sanity saving tips over here.