diff --git a/codes/test.py b/codes/test.py
index f8f2c0a4..23825695 100644
--- a/codes/test.py
+++ b/codes/test.py
@@ -18,8 +18,9 @@ import numpy as np
 def forward_pass(model, data, output_dir, opt):
     alteration_suffix = util.opt_get(opt, ['name'], '')
     denorm_range = tuple(util.opt_get(opt, ['image_normalization_range'], [0, 1]))
-    model.feed_data(data, 0, need_GT=need_GT)
-    model.test()
+    with torch.no_grad():
+        model.feed_data(data, 0, need_GT=need_GT)
+        model.test()
 
     visuals = model.get_current_visuals(need_GT)['rlt'].cpu()
     visuals = (visuals - denorm_range[0]) / (denorm_range[1]-denorm_range[0])
@@ -39,7 +40,6 @@ def forward_pass(model, data, output_dir, opt):
             save_img_path = osp.join(output_dir, img_name + '.png')
 
         if need_GT:
-            fea_loss += model.compute_fea_loss(visuals[i], data['hq'][i])
             psnr_sr = util.tensor2img(visuals[i])
             psnr_gt = util.tensor2img(data['hq'][i])
             psnr_loss += util.calculate_psnr(psnr_sr, psnr_gt)
diff --git a/codes/train.py b/codes/train.py
index 58b0ba3c..008af2cd 100644
--- a/codes/train.py
+++ b/codes/train.py
@@ -241,10 +241,6 @@ class Trainer:
                             sr_img, gt_img = util.crop_border([sr_img, gt_img], opt['scale'])
                             avg_psnr += util.calculate_psnr(sr_img, gt_img)
 
-                        # calculate fea loss
-                        if self.val_compute_fea:
-                            avg_fea_loss += self.model.compute_fea_loss(visuals['rlt'][b], visuals['hq'][b])
-
                         # Save SR images for reference
                         img_base_name = '{:s}_{:d}.png'.format(img_name, self.current_step)
                         save_img_path = os.path.join(img_dir, img_base_name)
diff --git a/codes/trainer/ExtensibleTrainer.py b/codes/trainer/ExtensibleTrainer.py
index 263271c0..abc88a51 100644
--- a/codes/trainer/ExtensibleTrainer.py
+++ b/codes/trainer/ExtensibleTrainer.py
@@ -46,8 +46,6 @@ class ExtensibleTrainer(BaseModel):
 
         self.netsG = {}
         self.netsD = {}
-        # Note that this is on the chopping block. It should be integrated into an injection point.
-        self.netF = networks.define_F().to(self.device)  # Used to compute feature loss.
         for name, net in opt['networks'].items():
             # Trainable is a required parameter, but the default is simply true. Set it here.
             if 'trainable' not in net.keys():
@@ -124,8 +122,6 @@ class ExtensibleTrainer(BaseModel):
             else:
                 dnet.eval()
             dnets.append(dnet)
-        if not opt['dist']:
-            self.netF = DataParallel(self.netF, device_ids=opt['gpu_ids'])
 
         # Backpush the wrapped networks into the network dicts..
         self.networks = {}
@@ -290,12 +286,6 @@ class ExtensibleTrainer(BaseModel):
                     os.makedirs(model_vdbg_dir, exist_ok=True)
                     net.module.visual_dbg(step, model_vdbg_dir)
 
-    def compute_fea_loss(self, real, fake):
-        with torch.no_grad():
-            logits_real = self.netF(real.to(self.device))
-            logits_fake = self.netF(fake.to(self.device))
-        return nn.L1Loss().to(self.device)(logits_fake, logits_real)
-
     def test(self):
         for net in self.netsG.values():
             net.eval()
diff --git a/codes/trainer/networks.py b/codes/trainer/networks.py
index ed64efb8..cc1104a3 100644
--- a/codes/trainer/networks.py
+++ b/codes/trainer/networks.py
@@ -70,44 +70,4 @@ def create_model(opt, opt_net, other_nets=None):
     if num_params == 2:
         return registered_fns[which_model](opt_net, opt)
     else:
-        return registered_fns[which_model](opt_net, opt, other_nets)
-
-
-# Define network used for perceptual loss
-def define_F(which_model='vgg', use_bn=False, for_training=False, load_path=None, feature_layers=None):
-    if which_model == 'vgg':
-        # PyTorch pretrained VGG19-54, before ReLU.
-        if feature_layers is None:
-            if use_bn:
-                feature_layers = [49]
-            else:
-                feature_layers = [34]
-        if for_training:
-            netF = feature_arch.TrainableVGGFeatureExtractor(feature_layers=feature_layers, use_bn=use_bn,
-                                                  use_input_norm=True)
-        else:
-            netF = feature_arch.VGGFeatureExtractor(feature_layers=feature_layers, use_bn=use_bn,
-                                                    use_input_norm=True)
-    elif which_model == 'wide_resnet':
-        netF = feature_arch.WideResnetFeatureExtractor(use_input_norm=True)
-    else:
-        raise NotImplementedError
-
-    if load_path:
-        # Load the model parameters:
-        load_net = torch.load(load_path)
-        load_net_clean = OrderedDict()  # remove unnecessary 'module.'
-        for k, v in load_net.items():
-            if k.startswith('module.'):
-                load_net_clean[k[7:]] = v
-            else:
-                load_net_clean[k] = v
-        netF.load_state_dict(load_net_clean)
-
-    if not for_training:
-        # Put into eval mode, freeze the parameters and set the 'weight' field.
-        netF.eval()
-        for k, v in netF.named_parameters():
-            v.requires_grad = False
-
-    return netF
+        return registered_fns[which_model](opt_net, opt, other_nets)
\ No newline at end of file