Stillen TruPower intake - Check Engine Light

I’ve recently installed a Stillen TruPower intake I purchased online from Redline360 ($335 after a $10 discount). Claim 20+ HP, 20+ lb ft torque.

Installation wasn’t too bad aside from the tight fitment and relocated air box grommet bolts that need to be reinstalled mostly by feel. Kit came with very basic paper instructions so a YouTube video came in handy.

Went with oiled filter option after some research suggested it has a deeper tone. Skipped the block off plate option.

It does sound good, throaty but not too loud. Definitely “sounds like” airflow volume has increased.

Initially throttle response increased and acceleration seemed improved; I was pleasantly surprised. Air/fuel mix and computer seemed to really click and truck was definitely more fun to drive.

After 15-20miles mix of highway and stop&go driving the check engine light came on and performance decreased dramatically. Bogging down and borderline limp mode.

Exact code wording in the vehicle alert screen: “A malfunction in the electronic control of the engine, throttle, or automatic transmission has been detected. Contact your Toyota dealer in order to have your vehicle inspected.”

I checked all hoses and connections (were fine) and disconnected the negative battery terminal and the CEL went away. Performance was similar to stock. After about 15mi it came back and performance decreased.

At this point I thought more hassle than it’s worth and asked Redline360 for a return label which they’re denying as they don’t accept returns on installed items. After some back and forth their suggestion is to get the truck tuned.

Truck is a lease through Ally (brokered by Jim R. on LeaseHacker forum - highly recommend) and was planning on returning to stock and selling the Stillen system before turn-in in 2.5yrs so tuning isn’t something I’d like to do.

Any suggestions, feedback, similar issues?

Anyone wanna buy a very low mileage intake?

2020 Tundra SR5 CrewMax Off Road.

 

Is the adapter at the throttle body maybe backwards? Looks to have a funny angle. MAF sensor plugged in on the back side and undamaged during installation. Very sensitive part.

 

https://www.tundras.com/threads/stillen-trupower-stage-2-cold-air-intake.69529/

Maybe re post here in this thread.

 

Get a dry filter.

 

You ever figure this out? I was all. It set to purchass this intakw but have seen 2 or 3 posts of peeps with the check engine light.

 

I got a check engine light last week, and I’m running the Stillen with a oiled filter.

Took it to Autozone for a scan, it was P0101 — check/replace MAF sensor.

Popped out the MAF sensor, gave it several sprays with QD Electronic Cleaner, and it’s been good since… which has been around 80 miles or so.

I don’t feel comfortable placing blame on the Stillen for it, prior to the Stillen intake I was running the TRD oiled filter for a few years so it’s not like this was unexpected for me. I’ve always accepted that when using oiled filters, CEL’s were a real possibility but thankfully easily remedied. I figure oil was probably building up on it over time.

Id be interested to see if anyone who got a CEL with the Stillen were using a dry filter.

 

Oiled filter. These trucks should never be ran with an oiled filter. The MAF sensor is too close to the intake opening to use an oiled filter. Any oil droplets on the MAF destroys it. Dry filters flow more and have higher filtration rates anyway. Ive had the Stillen intake with a dry filter for a year now and have zero issues.

 

My check engine light came back on, so I put a dry AFE filter on order since I didn’t feel like cleaning my MAF sensor every couple weeks if the increased airflow is fouling up the sensor this frequently.

It took about 200 miles for it to come on, then after 20 miles of driving it just went back off. So now I’m thinking it’s not the sensor getting fouled up, it might be more related to my DAP tune or maybe the filter swap from the included oiled K&N to oiled AFE.

I’ve towed the same equipment on the same 4mi stretch of highway this time last year when I first got the Stillen, and never got any codes. But this time last year, I was running the included K&N filter and I wasn’t tuned. At roughly the same time I’ve changed filters + got daptized.

I’ve read that Stillen changed from including K&N filters to using some other brand (it wasn’t AFE, but I forget the name)… so now I’m wondering if the different filter medium is throwing the MAF values just out of whack enough to throw the code under specific conditions.

The simplest explanation in my case would probably be the tune, but I can’t help but figure since the other forum users getting the code haven’t mentioned DAP at all that maybe it’s just the filter.

 

Good to know! My kit came in a couple weeks ago (dry filter version) and I’ve been waiting for time to install it.

 

I run dap
Stillen with a afe dry flo filter and flowmaster exhaust

I got the cel recently. No signs of bogging down or performance loss. Same p0101 code.

Anyone have a solution or did the code just stay away after clearing?

 

I cleared it and it came back (same stretch of road too), the second time around I just continued driving with it and the light went away on its own. It’s never come back. If you continue driving it should go away on its own too.

 

Having the same exact issue following my Stillen oiled CAI install. I should’ve just ordered the dry filter but I used an oiled previously and never had any issues. I cleaned the MAF sensor and after driving about 35 miles the CEL is still on (not sure if that’s enough to clear it). No symptoms of any kind really. Thinking about ordering a dry one, which AFE filter did you order for those that did? Or should I just keep driving it and see what happens?

 

You may be able to get it to reset by unhooking the battery for 20 mins after you've cleaned the MAF. If not you'll need a device like Scangauge or other OBD reader to clear the MAF code from the system.

As far as alternative filters you need one that has a 6" opening and is roughly the dimensions of the filter Stillen provided.

 

Awesome. Thanks. I do have an OBD reader and I just cleared it this morning. Fingers crossed. If it comes back on I’ll be switching filters.

 

No worries. AFE's search is pretty good. Easy to find what you need:
https://afepower.com/universal-air-filters

 

I’ll definitely be needing it, CEL just came back on.

 

I ran an oiled K&N for 2-3 years before making the switch to a dry AFE. Zero CELs from either. I do see how running a saturated (oiled) filter could foul up the MAF and never washed or oiled mine. When it was too dirty, I tossed it and got another.

 

Have you replaced the MAF or just cleaned it? Replacing the filter may not remedy the issue entirely if the current MAF is toast or on the way to failing.

 

Just cleaned it. That’s my fear that it’s permanently jacked now. I’m talking to stillen trying to get them to at least send me a dry filter.

 

MAF isn't too expensive to replace

My MAF shit the bed about 18 months after cleaning the MAF and replacing the filter with an AFE dry filter. With the oil filter in place it lasted a month or so before needing cleaning again.

 

Yeah, I should’ve just went with the dry filter. Oh well lesson learned. If I need a new MAF so be it. Of course I’m up for inspection this month. Emissions and safety in PA. Hopefully I can get it off long enough to get it inspected.

 

Hopefully I don't jinx myself, but after driving the truck about 150 miles or so with multiple clearing and returns of the CEL I decided to tear everything out (minus the air box) and start over. Removed the filter, removed the MAF, vacuum lines, and the connection to the throttle body. Cleaned the MAF again, tightened the white plastic adapter on the back of the air tube a bit more, even though I was worried about stripping it, realigned everything, meticulously checked for any gaps where air could get in and finally re-installed everything. I also put a prefilter on to prevent any water spray from getting sucked in. Cleared the code, started it up and have driven maybe 25 miles or so without any CEL. Considering the CEL would come on within 2-3 miles of driving previously I'm hoping whatever it was is now resolved. Fingers crossed....

 

Depends on your conditions but I found it is fairly hard to get water in the box. In my case the prefilter was too restrictive and tripped MAF codes. Take precautions as they fit your case.

 

@Nbab23 You may be better off running the front block off plate if you are worried about water intrusion; Stillen may be willing to sell you the kit if yours didn't come with it. You still get full air via the fender inlet and the filter is unrestricted. Another option is to stuff a rag or something in the front inlet.

Unless you are running with the fender liner off or fording deep waters you aren't likely to get water through your filter.

Again I don't know what kind of trails and routes you are running so take precautions accordingly.

 

Makes sense, I'm not doing anything that would take me into deep waters so no worries as far as that goes. My logic for the prefilter in addition to keep any water out was to actually restrict airflow a bit. The code with my intake was the MAF detecting too much air entering the engine which made me think I wanted A. To see if there were any leaks in the intake and B. See if perhaps restricting airflow just a bit would actually help not trip the code. If the CEL stays off and I can get it inspected I'll probably take the prefilter off and see what happens. I certainly don't want to lose the benefits of the CAI with a restrictive prefilter on there.